The Sensible Twin

[Grumph]

Subtitle should probably be "The bucket hacksaw"...

My version of what Speedpro has done - but unsupercharged...

Currently on final assembly. As Speedpro's version, the RHS of an FZR250 four - but this one is resleeved and bored to 53mm to use GSXR400 pistons.
Which coincidentally use the same dia gudgeon pins as the FZR. They're roughly 4mm higher compression height so a barrel spacer is required. As is a camchain 2 links longer. Straight out of the DID catalogue, from memory a GSXR400 one again.
I'm using a Kelford profile on the inlet cam, std exhaust.
Wallace bored the block to suit the liners I machined up, then finish bored them after I'd installed them.

Pic is cases ready to go together. Oil galleries to the unused mains tapped and grubscrews inserted to block them off. Crank cut, oil holes radiused and then it was linished. 3LN long rods used. I'd have preferred to use the early short rods but out of the roughly 1 1/2 broken motors I got from Husa, there was only one short rod...The mind boggles at the mixture that may have been used. Pistons are currently 30g heavier than the originals so I may yet have a cutting session.

More to come as it gets done.

[F5 Dave]

So what sort of frame will that go into? FZR seems the easy choice, if a little fat & heavy.

[Grumph]

So what sort of frame will that go into? FZR seems the easy choice, if a little fat & heavy.

I really haven't decided yet. The easy choice, not having an FZR frame handy, is the CBR250RR bare frame i have laying here. Given the motor has one wide shoulder, anything narrow will have a carb going through a frame rail.
The alternative of an assymetric trellis, right down to a single sided arm with the shock on the left where there are no cylinders, has appeal.
As i remarked to husa, where did i put the pic of the prototype White Power single sided fork...Assymetry gone mad, LOL.

Bear in mind too that i'm not looking at it as a Kart track bike. It looks like we're on biggerer tracks here for the forseeable future.

[speedpro]

Cool. Can we see how you blank off the cut end of the cylinder & head, and are you using the standard rotor?

[F5 Dave]

Linear bearing thingy, yeah I remember reading about those, maybe in ACMN.

[Grumph]

Cool. Can we see how you blank off the cut end of the cylinder & head, and are you using the standard rotor?

Yes, you will, I took some lessons from you, lol....Then did it differently.

At present a cut std rotor will be used. Ign will be total loss as i have no accessories to power. I first saw a cut alternator rotor on Sidecar Bob's 600 engines for Pinky. If it's good enough for the IOM, etc...basically, the swaged edge is turned off and the magnets removed, then the outer edge is cut back to the edge of the raised triggering lumps. So it's just used as a carrier for the trigger pieces. In the past i have made up alloy rotors with a steel trigger shoe screwed to them - adjustably mounted on the OE boss. This sucker has multiple triggers which i don't feel like duplicating. Any adjustment will have to be by offset keys.

[Grumph]

Linear bearing thingy, yeah I remember reading about those, maybe in ACMN.

Very cryptic Dave - but I assume you're referring to the single sided fork, yes AMCN rings a bell.

[Grumph]

Next installment. Cases together, barrel on. Used rings and pistons but the rings still had the ID marks discernable so not too bad.
Didn't lighten the pistons - lets see how bad it shakes first. The sides of the domes had to be trimmed slightly to fit the chambers.
A std base gasket, a 4mm alloy spacer and a .020in copper head gasket made by anonymous which came with the bits...then .010in off the barrel as a cleanup cut gave a measured .032in squish. That'll do.
The valve cutaways only needed the ex side made closer together. A shaky hand and the die grinder did that.
With the cams dialled in there's plenty of valve to piston clearance. I could have cut the head to get more compression but it measures up at 11.8 at present, again, that'll do.

[HenryDorsetCase]

I really haven't decided yet. The easy choice, not having an FZR frame handy, is the CBR250RR bare frame i have laying here. Given the motor has one wide shoulder, anything narrow will have a carb going through a frame rail.
The alternative of an assymetric trellis, right down to a single sided arm with the shock on the left where there are no cylinders, has appeal.
As i remarked to husa, where did i put the pic of the prototype White Power single sided fork...Assymetry gone mad, LOL.

Bear in mind too that i'm not looking at it as a Kart track bike. It looks like we're on biggerer tracks here for the forseeable future.

VFR400NC30 rolling chassis....? Swingarm on the left.....

[Grumph]

VFR400NC30 rolling chassis....? Swingarm on the left.....

Too narrow - the V4 is quite a skinny thing at head level, albeit heavy.

Other options may be opening up.

[Grumph]

A bit more progress. Head on, cams in on marks that I had to re-establish. They are of course swapped end for end and slots cut for cam location at the outer end. Machining there done by Wallace again, at least he's now got a cutter for that job...
Inlet is a Kelford grind, cut into the base circle, no welded buildup. About .020in more lift and around 20 degrees more duration at running clearances.
Springs are still a long way from coilbind, still about .25in clearance retainers to seals. Biggest shim needed was a 265.
This would be a good hopup for a std FZR250. If it seems exhaust restricted, I'll get the exhaust cam done too. There's room in the valve cutaways.
They're in on 103/104 lobe centers which I know works on bigger FZR's.


Sorry Speedpro, I'm not teasing you, I'll get pics of the other end.

[F5 Dave]

Fill the inlet port bottoms if they are like other period Yamahas.

[Grumph]

Fill the inlet port bottoms if they are like other period Yamahas.

Not needed for once IMO. Surprisingly good. Just some short side radius work needed.

I know what you mean though, the FZR600 Kev had was beautifully done - and we think by someone in Wellington.

[TALLIS]

Will be interesting to see what type of rpm it can actually achieve safety (20tho twin = awesome)

[Grumph]

Will be interesting to see what type of rpm it can actually achieve safety (20tho twin = awesome)

Define safely, lol...Pistons are 30g heavier which is pretty well 20%....Yes the rods are nuggety, particularly compared to say ZX400, but...

I'm thinking around 15 will do for a start. I see the stock power curve actually peaks around there so it's just passing air above that.

[dangerous]

Ya know were I am when you need a "sensible Pilot" :pinch:

[Grumph]

Ya know were I am when you need a "sensible Pilot" :pinch:

Yes....I'd point out that there are already a couple of what i'd call "skinny kids" sniffing round....

I may yet hold rider tryouts beside the Darfield ATM....

[dangerous]

Yes....I'd point out that there are already a couple of what i'd call "skinny kids" sniffing round....

I may yet hold rider tryouts beside the Darfield ATM....

hahah... WHAT, Im a kid and the not so skinny is pure mussle G required for hanging on to shear Itiallian grunt (in the paddock) :facepalm:

[Drew]

hahah... WHAT, Im a kid and the not so skinny is pure mussle G required for hanging on to shear Itiallian grunt (in the paddock) :facepalm:
My understanding was that some one's otalian grunt machine was too much for you, and spat you off.

[Grumph]

Just for Speedpro - the cut end of the head and barrel and how I've decided to seal it - initially anyway.

Barrel is cut as far back as possible commensurate with finding something to put screws into. Head to match.
Yes Dave that is filler in a couple of spots, it's unavoidable unless you do a fair amount of welding.
The wall thickness is such that I reckon the whole thing would distort if it was welded anyway.
The tapped hole which is cut through is actually a casting plug for the water jacket - not the plug hole.

Plate goes on covering the ends of the cam cover. Those ends have rubber channel bonded to them which is hard up against the plate.
If it weeps, I can easily dummy up some solid blocks to bolt on the cam cap position - then drill the plate and tap the blocks for another couple of screws.
We'll see if it's needed first.

[Autech]

There's an RGV250 rolling chassis on the trademe at the mo in Chch, not sure if that would do the job or not though as I have no experience stuffing large things into small spaces... Or is it small things into large spaces...


Yes....I'd point out that there are already a couple of what i'd call "skinny kids" sniffing round....

I may yet hold rider tryouts beside the Darfield ATM....

Sign me up! I weigh next to nothing so if you want to show everyone how fast it is on the Ruapuna main straight, I'm ya man, just excuse me for the corner bits :D

[Drew]

The best chassis for it is what it came out of, surely?

[Grumph]

The best chassis for it is what it came out of, surely?

Probably true. Thanks to the kindness of people on here, specifically Flettner and TZ350 i've been offered one.
Unless someone's coming South with room, it's looking like i may have to come up and fetch it.

[Grumph]

Sign me up! I weigh next to nothing so if you want to show everyone how fast it is on the Ruapuna main straight, I'm ya man, just excuse me for the corner bits :D

There's a reason for doing it beside the ATM...proof of ability to pay will be required.....

And yes, i saw the RGV, too dear for me - and again too slim. As is the CBR150 chassis I've been offered. Amazing what comes out of the woodwork.

[Drew]

Probably true. Thanks to the kindness of people on here, specifically Flettner and TZ350 i've been offered one.
Unless someone's coming South with room, it's looking like i may have to come up and fetch it.

Not till January for a south island trip for us. I think I've got some FZR rotors at home. 250 had a single disk, was it still 320mm?

[jasonu]

There's an RGV250 rolling chassis on the trademe at the mo in Chch, :D

It would win the 'heaviest bucket' competition...

[Autech]

There's a reason for doing it beside the ATM...proof of ability to pay will be required.....

And yes, i saw the RGV, too dear for me - and again too slim. As is the CBR150 chassis I've been offered. Amazing what comes out of the woodwork.

Haha, fair enough too! Will be interesting to see this run, lets hope whoever buys it sticks it on the track n not the shed!

I doubt that RGV will go for the full 1k, and as mention above it would be bloody heavy for a bucket. Great chassis from what I have heard though, usually spoken in hushed voices about how good they can take a corner


Sent from my iPhone using Tapatalk

[Grumph]

Haha, fair enough too! Will be interesting to see this run, lets hope whoever buys it sticks it on the track n not the shed!

I doubt that RGV will go for the full 1k, and as mention above it would be bloody heavy for a bucket. Great chassis from what I have heard though, usually spoken in hushed voices about how good they can take a corner


Yes, often by us old buggers who haven't woken up to the advances in frames and tyres since 1992...

At this point I rather like the idea of bringing it out with a guest rider for feature meetings - but I have almost enough bits for a second motor which might be for sale...

[Grumph]

Right - until i can get round to narrowing the ignition side, this is about as far as it goes at present.

Speedpro will note in the rear view that I did what I suggested to him and changed the water pump outlet to a tangential direction. In conjunction with an altered fitting on the back of the barrel this allows a short hose up and across. This loses the metal pipe going out and around...
Even though it now looks like it's going into an FZR250 frame I'm still trying to lose width where possible.
In line with this aim, I used the earlier sump which has a filter element fitting up from underneath. The late one which is interchangeable uses a spin on filter sticking out underneath the final drive sprocket.

It's finished up quite light. can't give a figure and it's certainly not an MB100 for weight - but not bad at all.

[husaberg]

Subtitle should probably be "The bucket hacksaw"...

My version of what Speedpro has done - but unsupercharged...

Currently on final assembly. As Speedpro's version, the RHS of an FZR250 four - but this one is resleeved and bored to 53mm to use GSXR400 pistons.
Which coincidentally use the same dia gudgeon pins as the FZR. They're roughly 4mm higher compression height so a barrel spacer is required. As is a camchain 2 links longer. Straight out of the DID catalogue, from memory a GSXR400 one again.
I'm using a Kelford profile on the inlet cam, std exhaust.
Wallace bored the block to suit the liners I machined up, then finish bored them after I'd installed them.

Pic is cases ready to go together. Oil galleries to the unused mains tapped and grubscrews inserted to block them off. Crank cut, oil holes radiused and then it was linished. 3LN long rods used. I'd have preferred to use the early short rods but out of the roughly 1 1/2 broken motors I got from Husa, there was only one short rod...The mind boggles at the mixture that may have been used. Pistons are currently 30g heavier than the originals so I may yet have a cutting session.

More to come as it gets done.

I think I seen might have seen a rod the other day?

[Grumph]

I think I seen might have seen a rod the other day?

Too late now. Any progress on that download ? Do I need to send you a flashdrive ?

[husaberg]

Too late now. Any progress on that download ? Do I need to send you a flashdrive ?

I forgot all about it.........

[Grumph]

Browsing the local VCC swap meet today, found these....Keihins, Downdraft, 28mm at the slide tapering to 30mm at the engine end.
Obviously 2 stroke origin but VERY close together. They'll go on the twin nicely.

Any suggestions as to engine of origin ?

[Drew]

NSR I would guess.

[husaberg]

NSR I would guess.

Yip or NS250 they were similar.

Browsing the local VCC swap meet today, found these....Keihins, Downdraft, 28mm at the slide tapering to 30mm at the engine end.
Obviously 2 stroke origin but VERY close together. They'll go on the twin nicely.

Any suggestions as to engine of origin ?
Ta06 is off the NS250
Greg whats the code on the side. TA10?
If so that makes them a MC16

http://tech.nsr-world.com/nsr250/all-nsr250/nsr250-stock-carb-settings.php
Venturi Diameter
28mm
Type
TA10A
Float Height
13mm
Main Jet
#110
Slow Jet
#38
Needle
No.1 2QY
No.2 2QZ
Idle Speed
1200 ± 100rpm
Throttle Free Play
2~6mm
Air Screw Position
1½ Turns out from fully closed

Was the flash drive helpful?
If you wanted something a little smaller, Drews Bro might still have a similar set of 24mm of a MVX250.

[Drew]

Yip or NS250 they were similar.

Ta06 is off the NS250
Greg whats the code on the side. TA10?
If so that makes them a MC16

Was the flash drive helpful?
If you wanted something a little smaller, Drews Bro might still have a similar set of 24mm of a MVX250.

I've got the MVX carbs at my place. From the spare bike.

[husaberg]

I've got the MVX carbs at my place. From the spare bike.

measure them up i had a feeling they were 24 but they might be 25 or 26mm

[Drew]

measure them up i had a feeling they were 24 but they might be 25 or 26mm

No need to measure. They're 26mm. That's why they didn't get separated and stuck on whatever bucket I was slapping together at the time.

[ellipsis]

...funny things those carbs...very slippery things...

[Grumph]

Yip or NS250 they were similar.

Ta06 is off the NS250
Greg whats the code on the side. TA10?
If so that makes them a MC16

Was the flash drive helpful?


Yeah, TA10. Thanks - i didn't have much to do with those NS250's when they were being raced here, I'd never seen the carbs off one.
I know there was at least one MC16 wrecked down here but the later NSR's were rocking horse poo in the SI.

Yes, flash drive is good thanks. Some odd stuff on there though - I may have to loan it to Neil for the TZR125 info....

[husaberg]

Yeah, TA10. Thanks - i didn't have much to do with those NS250's when they were being raced here, I'd never seen the carbs off one.
I know there was at least one MC16 wrecked down here but the later NSR's were rocking horse poo in the SI.

Yes, flash drive is good thanks. Some odd stuff on there though - I may have to loan it to Neil for the TZR125 info....
That might have been a mistake, are you sure 125?
Was there some NSr125 stuff, I think that was for Bren i think?
Wob posted something about the carbs a week or two ago, i think some of the FCR stuff might fit.
Scott had one on the GPR150 at one stage also the GPR100 twin has them as well.

[Grumph]

that might have been a mistake are you sure 125?
Was there some NSr125 stuff I think that was for Bren i think?
Wob posted something about the carbs a week or two ago, i think some of the FCR stuff might fit.
Scott had on on the GPR150 at one stage and the GPR100 twin has them as well.

Had a quick browse through the flash drive and after i'd seen what i needed, the rest is a blur....
I'd expect that quite a bit of normal keihin jetting will fit. i'm confident i can get them to work.

[Drew]

Had a quick browse through the flash drive and after i'd seen what i needed, the rest is a blur....
I'd expect that quite a bit of normal keihin jetting will fit. i'm confident i can get them to work.

Solder the pilot jets and bust out your twist drills old boy.

[Grumph]

Solder the pilot jets and bust out your twist drills old boy.

Still got the set you could buy below 1mm - and made up a set in 1986 from 1.0mm to 3.0mm in .05mm steps.
You're talking to the (ex) guru of jetting for methanol at national level when it was still legal....

[F5 Dave]

Oh dear, that's in my future probably Sunday with some old nail. I told him to ring a spare extinguisher. I'm not sure how clued up I want to become.

MikeS sent me some NSR carbs if you run out of bits I'll send them down. Wasn't enough of an improvement on the 50 to continue, or in fact any improvement over pwk with two kinks in manifold.

[Grumph]

Contrary to popular belief, neither this project nor I are totally stagnant. Managed a little progress.

The 250 chassis (ex Beast V1.0) had sat for too long so it's been part restoration, part fabrication.
Engine in, radiator mounted (stock 250). Brakes unseized, calipers cleaned up. Front disc which had been very skilfully reduced to 3.0mm thickness has been replaced with a good stocker (thanks Wallace) - but still 320 OD. I didn't like the thin disc for use on full circuit ruapuna or Timaru - even with a skinny kid on board.

Still to do a replacement subframe. Want a 'glass tank copy as a cover for a small in-frame tank. Still to mount carbs/coils etc....

[Drew]

Standard subframe on those is made of cheese. 5/8 pipe, 1mm wall and you can knock up something stronger and lighter for about $60

[Grumph]

Standard subframe on those is made of cheese. 5/8 pipe, 1mm wall and you can knock up something stronger and lighter for about $60

Have a stack of 3/4in 1.6mm wall MS - and gas in the bottles....already machined the ends to bolt through to the frame.
And replacing the big FZR seat with the cliche'd TZ G/H seat...
I've done several subframes in 3/4in - and the big virtue is that they're crashable.
Actually, thinking back, around 17 - 18 subframes. Shit, i've been doing it a while...

[Grumph]

Progress is slowly being achieved. Carbs are ready to go on and have a cable made up. I suppose having found room for the battery and coils I'll have to wire it too...
I looked at all that room down the left of the cylinder block and thought I'd better put something heavy in there. Battery and TCI box on the outside,coils on the inside. Hung on urethane as are the front engine hangers carrying the std radiator. There's not a lot of mounting points for this stuff in this frame...

[TZ350]

Looking good, very interesting engine.

[Grumph]

Looking good, very interesting engine.

Only if it runs as well as hoped, LOL.

Rob do you remember what the deal is with the LH footrest assembly ? No pivot point for the rearset gear lever on the one fitted. Did you put two RH ones on it ? Probably didn't need the OE gearshift setup...

[TZ350]

Rob do you remember what the deal is with the LH footrest assembly ? No pivot point for the rearset gear lever on the one fitted. Did you put two RH ones on it ? Probably didn't need the OE gearshift setup...

332356

It was a while ago so not sure exactly what I did or why but looks like I used a reverse lever setup. Post a close up of the hanger and foot rest and Monday I will see if there is one at work.

[Drew]

Only if it runs as well as hoped, LOL.

Rob do you remember what the deal is with the LH footrest assembly ? No pivot point for the rearset gear lever on the one fitted. Did you put two RH ones on it ? Probably didn't need the OE gearshift setup...
FZR has a bolt that the lever pivots on.

[Grumph]

It was a while ago so not sure exactly what I did or why but looks like I used a reverse lever setup. Post a close up of the hanger and foot rest and Monday I will see if there is one at work.

Thanks - it looks a bit different now, eh. I ditched the tape on the front guard and had it plastic welded. Must make up a new mount/fork brace tomorrow.

it's hard to pick just what should be there for a lever mount, from the parts books.

[mr bucketracer]

looking good , i can't wait to hear it run ! should go real well

[Drew]

So using the two slugs from one side, it runs cross plane Yeah? Or have you made a crank?

[Grumph]

So using the two slugs from one side, it runs cross plane Yeah? Or have you made a crank?

Go back to the first pic - normal 4 cyl crank cut in the middle so it's one up and one down. Given the loads involved I could probably cut and weld to get a twisted twin - say 90 deg phasing. But is it worth it in this small size ?

[Drew]

Go back to the first pic - normal 4 cyl crank cut in the middle so it's one up and one down. Given the loads involved I could probably cut and weld to get a twisted twin - say 90 deg phasing. But is it worth it in this small size ?

Yeah, cross plane then. Will fire at 180 degrees then be dead for 540.

I doubt it will make any difference at that sort of capacity. My experience with the crossplane R1 is that they're snatchy and fucking horrible.

[Grumph]

It was a while ago so not sure exactly what I did or why but looks like I used a reverse lever setup. Post a close up of the hanger and foot rest and Monday I will see if there is one at work.

Sorted thanks Rob - You'd shortened the LH footrest which the pedal pivots on. Obviously you didn't need the extra length.
A stepped spacer machined up with a longer retaining bolt gives me somewhere to put the pedal.

[husaberg]

Yeah, cross plane then. Will fire at 180 degrees then be dead for 540.

I doubt it will make any difference at that sort of capacity. My experience with the crossplane R1 is that they're snatchy and fucking horrible.

Flat plane Drew, if the crank was 90 degree it would be crossplane.
http://www.cycleworld.com/2015/08/18/ask-kevin-cameron-what-are-the-benefits-of-a-flat-plane-crank

[Drew]

Flat plane Drew, if the crank was 90 degree it would be crossplane.
http://www.cycleworld.com/2015/08/18/ask-kevin-cameron-what-are-the-benefits-of-a-flat-plane-crank
Na. A 4 runs at 90° to be cross plane. But play the percentages, a twin is crossplane at 180°.

[husaberg]

Na. A 4 runs at 90° to be cross plane. But play the percentages, a twin is crossplane at 180°.

A 180 crank is a single plane, look down the end of the crankshaft. the crankpins are in a single plane its not rocket surgery.
Gregs crankshaft is a 180 crank
https://en.wikipedia.org/wiki/Crossplane
pay special attention to the last paragraph.

[F5 Dave]

Wouldn't it run better if it made some power every time the piston came to the top?

[Grumph]

Wouldn't it run better if it made some power every time the piston came to the top?

As it hasn't run yet Dave, I'll take that under consideration....Go and have another drink.
And as it's my thread and I make the rules, the crank is a single plane....

Why do the awkward buggers live in Wellington ?

[flashg]

Na. A 4 runs at 90° to be cross plane. But play the percentages, a twin is crossplane at 180°.Yamaha MT07 is a crossplane crank twin @ 270° according to Yamaha. They've been making twins with a 270° crank for a number of years, starting with the TRX 850 from memory. Could be wrong though.

[flashg]

Yamaha MT07 is a crossplane crank twin @ 270° according to Yamaha. They've been making twins with a 270° crank for a number of years, starting with the TRX 850 from memory. Could be wrong though.Also if I remember correctly, The 270° crank was developed as it fires exactly the same as a Ducati L engine, but was more compact being a parallel twin, allowing the engine to be placed more strategically in the chassis to help with handling etc.

[Drew]

Hmmm. My understanding was skewed it seems. I'd never thought of it past the firing times. But that makes sense to think of it from a mechanical view down the crank.

So TDM and TRX are cross plane then. Those are quite a nice motor. Wonder why the R1 was so horrid.

[Grumph]

Hmmm. My understanding was skewed it seems. I'd never thought of it past the firing times. But that makes sense to think of it from a mechanical view down the crank.

So TDM and TRX are cross plane then. Those are quite a nice motor. Wonder why the R1 was so horrid.

Possibly because having ensured that they had lower torque losses because of the spacing of power impulses, they decided that they didn't need as much flywheel....It would be interesting to try one with more crank weight.
Watching one of the few C-P R1's racing at levels last season, it was apparent that there was very little extra throttle needed to go from all the tyre could take to serious wheelspin. A vigorous rider could and did get it sideways and spinning too often for comfort.

[Drew]

Possibly because having ensured that they had lower torque losses because of the spacing of power impulses, they decided that they didn't need as much flywheel....It would be interesting to try one with more crank weight.
Watching one of the few C-P R1's racing at levels last season, it was apparent that there was very little extra throttle needed to go from all the tyre could take to serious wheelspin. A vigorous rider could and did get it sideways and spinning too often for comfort.
My initial thought had been that the fly by wire was crap. But that can be tuned and nobody was getting improvement from that. So you're possible right.

[F5 Dave]

I rode a mates R1M back roads around wairarapa and it was the easiest thing to ride fast I've ever been on. Way too easy for semblance of safety. Never ridden the newer standard R1 to compare.

[Drew]

I rode a mates R1M back roads around wairarapa and it was the easiest thing to ride fast I've ever been on. Way too easy for semblance of safety. Never ridden the newer standard R1 to compare.
They must have made them better with the newer ones I can only guess.

[flashg]

Hmmm. My understanding was skewed it seems. I'd never thought of it past the firing times. But that makes sense to think of it from a mechanical view down the crank.

So TDM and TRX are cross plane then. Those are quite a nice motor. Wonder why the R1 was so horrid.You're right about firing pattern for the R1, 0°,90°,180°,270°. Followed by the exhaust strokes in the same order. Apparently no inertia, a blip of the throttle is instant. The R1 crank can roll freely on a table. Colin Edward's did this on the promotion of the cross plane crank back in the day. The whole concept was aimed at tyre recovery between pulses as a twin does. The crank is said to be heavier and stronger to handle the extra stresses caused by its design and firing pattern.
PS I have no idea of the firing order, no reason it couldn't be standard.
I'd love to know the firing pattern of the current triple if anyone knows. Crossplane maybe ?

[flashg]

Google helpedhttps://uploads.tapatalk-cdn.com/20170827/91673edb0e427d2ddc5c41644af9a2ec.jpg

[Grumph]

Meh, calling a 120deg triple a crossplane crank is like calling the sky blue. it's the only seriously practical way of balancing a triple.

And yes, I know all about the 180deg flatplane crank Laverdas. Worked on them, like them, but they're not smooth by comparison to a 120.

[speedpro]

Marketing departments aren't famous for letting facts or common sense get in the way of a promotion

[Triplenut]

Hi Greg,
good to see you making some progress on this.

I have an FZR thou fibreglass copy tail piece FOC if you want it ?
Was originally on my first FZ race bike, white with red stripe.


Cheers
DR

[TZ350]

332411

I was traveling in the South Island this week and made the pilgrimage out to Grumps place. Where he was working on his latest project, the twin cylinder 150 made from cutting down a four cylinder engine and crank.

332410332412

Even though the original four cylinder motor looks quite bulky it is much lighter than I thought. The half crank is very light and the primary drive and gearbox is much lighter than comparable FXR150 parts.

But the best part is that the twins RPM ceiling is about 18,000 rpm while the FXR150 is about 12,000. There is big performance possibilities in that extra 6,000.

[mr bucketracer]

332411

I was traveling in the South Island this week and made the pilgrimage out to Grumps place. Where he was working on his latest project, the twin cylinder 150 made from cutting down a four cylinder engine and crank.

332410332412

Even though the original four cylinder motor looks quite bulky it is much lighter than I thought. The half crank is very light and the primary drive and gearbox is much lighter than comparable FXR150 parts.

But the best part is that the twins RPM ceiling is about 18,000 rpm while the FXR150 is about 12,000. There is big performance possibilities in that extra 6,000.good stuff rob making it to the masters place

[Grumph]

good stuff rob making it to the masters place

He did very well finding me at all...

Good to have some time to discuss things away from the pressure of a race day.

Edit - The good looking stock crank I'm holding is one of the ones from Husa - the alternator end is broken off it. Prob accident damage....

[ellipsis]

...I thought Grumph was a really old and wizened featured chap, not that young looking, finely sculpted chap...are you sure that is not an imposter or you went to the wrong house?...

[Grumph]

...I thought Grumph was a really old and wizened featured chap, not that young looking, finely sculpted chap...are you sure that is not an imposter or you went to the wrong house?...

I looked at that and thought, shit photos CAN lie....LOL

Next passport pic you need Neil, book a visit from Rob.

[husaberg]

He did very well finding me at all...

Good to have some time to discuss things away from the pressure of a race day.

Edit - The good looking stock crank I'm holding is one of the ones from Husa - the alternator end is broken off it. Prob accident damage....
Aye it was broken when husa got it, ;)Fyi Speedpro has the other end and mag rotor.
I gave a head to either Scott or Neil i can't remember who?
I still can't find any spare cam covers but i did find a piston and rod the other day Greg.
I am over at shefield for Rugby on the 16th Greg, if you want me to drop it at the garage?

[Grumph]

Aye it was broken when husa got it, ;)Fyi Speedpro has the other end and mag rotor.
I gave a head to either Scott or Neil i can't remember who?
I still can't find any spare cam covers but i did find a piston and rod the other day Greg.
I am over at shefield for Rugby on the 16th Greg, if you want me to drop it at the garage?

Thanks but no. Got more than enough std pistons. And enough rods.
Hororata swap meet is the 16th.....

[mr bucketracer]

Aye it was broken when husa got it, ;)Fyi Speedpro has the other end and mag rotor.
I gave a head to either Scott or Neil i can't remember who?
I still can't find any spare cam covers but i did find a piston and rod the other day Greg.
I am over at shefield for Rugby on the 16th Greg, if you want me to drop it at the garage?I got a head of you ,can't remember if it have a cam cover with it

[Grumph]

To enlarge on what I said - I picked up another motor from Seraph down Timaru way which has a dropped valve on the LHS but is complete so no more yam bits needed.
What I could use is another pair of gsxr400 pistons and rings. GK71B I think - the first version 400.

[Grumph]

Well, while waiting for a couple of ignition boxes, I got the subframe done.
To make Drew happy I did it in 5/8in 16G mild. Bronze welded.
When i get the chance, I'll set up the scales and see how much lighter than the cut OE subrame it is.
The TZ G/H seat doesn't look too bad tacked onto the alloy beam frame IMO - and I just fit onto it, LOL.

[Buddha#81]

The TZ G/H seat doesn't look too bad tacked onto the alloy beam frame IMO - and I just fit onto it, LOL.

I'm guessing you don't want me to ride it........ there is no way ill get my fat guts in between the tank and seat

[robajs]

the bike is so bloody tiny most full size adults would find it a tight fit! let alone those of us who are plus size units:facepalm:
happy to lift that motor in and out......the gs motors and that blood laverda were heavy.

[Grumph]

I'm guessing you don't want me to ride it........ there is no way ill get my fat guts in between the tank and seat

You might be surprised - I'm probably as portly as you now. When I get around to doing a tank cover and small in frame tank, the bloody cover will certainly be a lot lower...I remember the last shop 250 Suzuki at McCleary's, the back of the tank was cut at 45 deg to let Tommy fit on it. Just like Neil's bucket....
The distance to seat/seat to pegs is pretty much the same as my F3 kawasaki 500 - which I fitted when I was a tad slimmer....
Anyway, I've only got to ride it to sort the carburation....

[husaberg]

bump.............

[speedpro]

A little while back I was sorting stuff out in John Connor's shed. He has the GSXR ignition that I made an adaptor for to get my FZR going initially. It was just sitting in an ice cream container on the bench. He had more or less cleared out the rest of his garage. He might be worth getting in contact with if you are still looking for an ignition. I know it worked and it has everything to make it fit.

[Grumph]

A little while back I was sorting stuff out in John Connor's shed. He has the GSXR ignition that I made an adaptor for to get my FZR going initially. It was just sitting in an ice cream container on the bench. He had more or less cleared out the rest of his garage. He might be worth getting in contact with if you are still looking for an ignition. I know it worked and it has everything to make it fit.

Don't know him - but yes, shit yes, I'm interested. None of the ignition boxes I have here work and Wallace was kind enough to play with a couple for no reward. He's been pushing a very good deal indeed on an ignitech - which is still out of my price range.
How do I contact John Connor ? And thanks very hard indeed.

[Grumph]

bump.............

Bastard...you have too much time to remember dead threads. See previous post, if a working ignition can be found things could move quickly.
Well, relatively...

I've still got this idea in my mind of how I want the pipes - and I still haven't found suitable tight 1 1/8in OD bends for the first part...

[husaberg]

Bastard...you have too much time to remember dead threads. See previous post, if a working ignition can be found things could move quickly.
Well, relatively...
All i have at the moment id time suely there must must be enough dyna or similar triggers tucked away.
Personally in the name of expediency i remember highwayman or Mike Moore doing something on a lil 175 or 200 honda with two pitbike inner rotors mounted back to back
I would be happy to sponsor one if it didn't work i could find a use for it.
they are on trademe use std honda taper and come complete with coils cdi etc. (Edit it might need a Coil)
https://www.trademe.co.nz/motors/motorbikes/parts-for-sale/electrics/listing-1819377957.htm
https://image.dhgate.com/0x0/f2/albu/g2/M00/44/71/rBVaG1UqowaASXfGAABfqIWXGZ4669.jpghttps://www.blygo.com.au/media/catalog/product/cache/1/thumbnail/9df78eab33525d08d6e5fb8d27136e95/8/_/8_2_12.jpghttps://www.blygo.com.au/media/catalog/product/cache/1/thumbnail/9df78eab33525d08d6e5fb8d27136e95/6/_/6_2_26.jpghttps://unitedexpressdist.3dcartstores.com/assets/images/STTR-0023d.jpghttps://ae01.alicdn.com/kf/HTB12iIWHx9YBuNjy0Ffq6xIsVXaj.jpghttps://ae01.alicdn.com/kf/HTB1d2g6HACWBuNjy0Faq6xUlXXa8.jpg

[Grumph]

All the stand-alone magnetic triggers - Dyna etc - and self generating mags like chainsaws and pitbikes, run into a wall at about 15000 RPM.
Ironic as coils since the 60's have been capable of 18000 sparks/min.
I've got magnetic triggers here - not Dyna but similar to Pertronic - which I picked up in a stock clearout on trademe.
I've looked long and hard at running them at half engine speed - but a compact drive which is reliable is a problem.
Neil's 4T twin project has run into the same problem - I understand he's currently thinking about it.

Ideally, I'd re-engineer the camchain tunnel and run a spare cam sprocket up against the chain for a half-speed drive.

[husaberg]

All the stand-alone magnetic triggers - Dyna etc - and self generating mags like chainsaws and pitbikes, run into a wall at about 15000 RPM.
Ironic as coils since the 60's have been capable of 18000 sparks/min.
I've got magnetic triggers here - not Dyna but similar to Pertronic - which I picked up in a stock clearout on trademe.
I've looked long and hard at running them at half engine speed - but a compact drive which is reliable is a problem.
Neil's 4T twin project has run into the same problem - I understand he's currently thinking about it.

Ideally, I'd re-engineer the camchain tunnel and run a spare cam sprocket up against the chain for a half-speed drive.

Id agree i thought the senisable twin was only aiming for arround 15k
I set up a H100 to run a std CDi from a XR200 to try a flat curve ignition std everything else
As you know the 125+cc Hondas run the trigger off the cam as STD
With the MB set up firing at Crankshaft speed it wouldn't rev over about 10K
There was a mini set up they used to use on KT's and similar that came from an accessory Chainsaw set up that used to be sold as a generic set up that used to run 17K plus.
I think from how Mike did his twin set up you could cam trigger.
What ever the set up was on a VT250 they were triggered i think from the crank with mags and revved very high.
Ibwould have thought you would have access to FZR400 and NC30 stuff?

[speedpro]

You already have a half-speed drive, it runs the cams. Just remember that the original ignition ran at crank speed and worked. Push comes to shove it isn't going to be a problem

[Grumph]

You already have a half-speed drive, it runs the cams. Just remember that the original ignition ran at crank speed and worked. Push comes to shove it isn't going to be a problem

True. Non exup ignition box ordered off alibaba...
I'm spending money like a drunkem sailor, fuel pump purchased, clutch cable found still to be paid for.
As there's a gap in the traffic here, I've started to make the in-frame tank. Goes away for welding of the main box seams tomorrow.
Once that's done, I'll make up the fittings. Got a cap - Ford Fiesta oil filler and alloy surround. $19 from pick-a-part. The alloy surround was disguised as a rocker cover...

Decided that if I can't make the pipes the way I want, I'll do them how I can. Wanted them side exit in front of the motor, they'll be under the motor now.
Uses bends I can get rather than ones I can't...

[husaberg]

True. Non exup ignition box ordered off alibaba...
I'm spending money like a drunkem sailor, fuel pump purchased, clutch cable found still to be paid for.
As there's a gap in the traffic here, I've started to make the in-frame tank. Goes away for welding of the main box seams tomorrow.
Once that's done, I'll make up the fittings. Got a cap - Ford Fiesta oil filler and alloy surround. $19 from pick-a-part. The alloy surround was disguised as a rocker cover...

Decided that if I can't make the pipes the way I want, I'll do them how I can. Wanted them side exit in front of the motor, they'll be under the motor now.
Uses bends I can get rather than ones I can't...

I have a rather nice pic of a factory Yamaha superbike pipe rather interesting con fig used on Edwards bike think.
340937
Or RC115
340934340935340936

[Grumph]

All the fours are using 4:2:1 setups now. Problem is you need a sophisticated computer program to work them out.

Over the years I've tried probably every joined up layout for 180 deg twins you can think of. All generally give a wide spread of power if done right.
All generally lose out right at the top end. As I've built mainly for Ruapuna and Levels - and biggish bikes - I've gone for spread over top end.
This thing is going to have to be biased for top end power as it will have to run on full track Ruapuna.

So it's individual pipes, stepped and tapered. And short....

[husaberg]

All the fours are using 4:2:1 setups now. Problem is you need a sophisticated computer program to work them out.

Over the years I've tried probably every joined up layout for 180 deg twins you can think of. All generally give a wide spread of power if done right.
All generally lose out right at the top end. As I've built mainly for Ruapuna and Levels - and biggish bikes - I've gone for spread over top end.
This thing is going to have to be biased for top end power as it will have to run on full track Ruapuna.

So it's individual pipes, stepped and tapered. And short....

Have a look at the double joints the twin balance pipes i cant figure it out, although i have seen similar on an Avaponic for some bike.
i like the RC115 though just for nostalgia

[F5 Dave]

There's always the 1/2 gear lever.

[Grumph]

Have a look at the double joints the twin balance pipes i cant figure it out, although i have seen similar on an Avaponic for some bike.
i like the RC115 though just for nostalgia

The top junction pipes are as you'd expect. The lower ones look to me like "I've got the time and the argon, what the hell, it'll baffle the opposition"





There's always the 1/2 gear lever.

Too cryptic for me Dave.

[speedpro]

Some call it the clutch. I figure the FZR will take a bit of abuse if required.

[husaberg]

Some call it the clutch. I figure the FZR will take a bit of abuse if required.

One of the ones here looks like it may have imploded.
but its a 45-60hp clutch by the looks of it.


The top junction pipes are as you'd expect. The lower ones look to me like "I've got the time and the argon, what the hell, it'll baffle the opposition"
Too cryptic for me Dave.
Id would agree by that was the fastest year for it, oldest bike and still won a race that year. modern mx bikes often have resonator tubes to broaden HP curves i wonder if thats what the lower half of them are. they act if the pipes longer at longer revs. plus drop a few DB's.

[Grumph]

Some call it the clutch. I figure the FZR will take a bit of abuse if required.

I was surprised to do a side by side comparison to a 400 clutch. Primary gear same tooth count - 250 narrower.
Basket uses same plates - 250 again narrower.
If you wanted/needed to, you could uprate it to a 400 clutch.
Might be useful to know if your turbo ever produces enough HP...

[Grumph]

Id would agree by that was the fastest year for it, oldest bike and still won a race that year. modern mx bikes often have resonator tubes to broaden HP curves i wonder if thats what the lower half of them are. they act if the pipes longer at longer revs. plus drop a few DB's.

Probably two reasons for going well that year - Edwards got on well with it. And at a guess, Yamaha finally put the cams in the right place. They persisted with a very odd lobe center setup even in the kitted stuff.
I'd doubt if the lower joiners have any effect at all. When Yosh started marketing pipes with joiners years back, I tried them on my pipes for various things.
They work if they're at a point where the energy in the gas is still high.

[husaberg]

Probably two reasons for going well that year - Edwards got on well with it. And at a guess, Yamaha finally put the cams in the right place. They persisted with a very odd lobe center setup even in the kitted stuff.
I'd doubt if the lower joiners have any effect at all. When Yosh started marketing pipes with joiners years back, I tried them on my pipes for various things.
They work if they're at a point where the energy in the gas is still high.
I seen this the other day
http://www.factorypro.com/ some people don't want help.
Those 5 valves are either top speed or acceleration never both They could be fast through the traps but not on the laps.
Everything i have ever seen suggests, Give them decent comp and they accelerate well but have no top speed. and visa vera i dont think there is any real way arround it.
Great on the street in low tune but not on the track.
Rossi got them to get rid of the 5 valve as they wanted to win more than they cared about corporate pride.
the resonance tubes are a little different they work well at lower velocities and they have only a drilling entry hole to not effect top end. in the pic the angle to me suggests the lowers are closed in the middle. as the angle is silly.
They could have easier joined them front to back but didn't.
340938
We could likely find out i guess someone will know for sure.
Maybe they were just there to hold the pipes together for easier fitment.

[Grumph]

Little things are getting done. Clutch cable - Phazer - arrived and fitted. Perfect length. Bar ends done. Sorry Rob - what was there I didn't like. Large rough lumps of nylon. Smaller, tidy lumps of nylon now. Pipes made. Rough enough, we'll see how it runs on them. Mounting the dinky alloy mufflers is a pain. Under the motor so SFA there to mount to. RHS will have a hanger from the bottom two screws on the clutch cover. LHS at present looks like it'll hang from the oil drain plug, LOL. It's a substantial lump of sump casting in just the right place - with a large dia screw in it.

Tank stage 1 won't be back till next week at the earliest so it's carry on with things like mounting instruments and the OE top fairing. When the new ignition arrives I'll mock up the ignition and spin it over...

Apropos of this - spinning it over - I'd seen Steve Ward starting the fleet of RS125's with a battery drill...And thought, hmm, mine's only 75cc cylinders...
The one-way socket used by RS125 owners is ex the US and quite expensive (by my standards) so I looked for an alternative.
Found a "ratchet adaptor" locally - 3/8 drive male one end, female the other, about 40mm long and 30 OD. An inline ratchet - reversible. $40 off the shelf in ChCh. Used with a 10mm hex X 3/8drive ex my set here in a drill and a long 14mm inpact socket on the other end, It'll do to spin this thing over I think.
And I can use it with any 3/8 drive socket - unlike the ones from the US.

[husaberg]

Little things are getting done. Clutch cable - Phazer - arrived and fitted. Perfect length. Bar ends done. Sorry Rob - what was there I didn't like. Large rough lumps of nylon. Smaller, tidy lumps of nylon now. Pipes made. Rough enough, we'll see how it runs on them. Mounting the dinky alloy mufflers is a pain. Under the motor so SFA there to mount to. RHS will have a hanger from the bottom two screws on the clutch cover. LHS at present looks like it'll hang from the oil drain plug, LOL. It's a substantial lump of sump casting in just the right place - with a large dia screw in it.

Tank stage 1 won't be back till next week at the earliest so it's carry on with things like mounting instruments and the OE top fairing. When the new ignition arrives I'll mock up the ignition and spin it over...

Apropos of this - spinning it over - I'd seen Steve Ward starting the fleet of RS125's with a battery drill...And thought, hmm, mine's only 75cc cylinders...
The one-way socket used by RS125 owners is ex the US and quite expensive (by my standards) so I looked for an alternative.
Found a "ratchet adaptor" locally - 3/8 drive male one end, female the other, about 40mm long and 30 OD. An inline ratchet - reversible. $40 off the shelf in ChCh. Used with a 10mm hex X 3/8drive ex my set here in a drill and a long 14mm inpact socket on the other end, It'll do to spin this thing over I think.
And I can use it with any 3/8 drive socket - unlike the ones from the US.

Wouldn't an Air Cylinder and a Impact driver be way cooler and make a better whirring noise.

https://www.youtube.com/watch?v=hOoYU5oPoWo

i thought you would just use a sprag clutch of an old starter say off a Pitbike bendex
https://i.ebayimg.com/images/g/uTwAAOSwkERcB~TL/s-l300.jpg
But off the shelf i can't picture it.

[F5 Dave]

Yeah ease of starting was a reason I didn't buy a mate's 256 Rotax GP bike, but a set of rollers or a drill starter would have fixed it. Hadn't really seen them back then. . . Circa 15 yrs back.

Being post 82 was the final nail and we don't do Bears up here really. Good chch bike.

[Grumph]

Without looking at the pics you've posted, remember that this would need to spin clockwise. Right-side kickstarts go the wrong way, left side ones are rocking horse poo.
This is the assembly. Hex end goes in drill, little dohickey in the middle is the in-line ratchet.

[F5 Dave]

Think a mate made something like that for Rogans RS.

[husaberg]

Without looking at the pics you've posted, remember that this would need to spin clockwise. Right-side kickstarts go the wrong way, left side ones are rocking horse poo.
This is the assembly. Hex end goes in drill, little dohickey in the middle is the in-line ratchet.

I thought you had joined the internet 1999 revolution and Horrarata had got broadband?
i was picturing the one way clutch of a tiny Starter motor

[Grumph]

Yeah ease of starting was a reason I didn't buy a mate's 256 Rotax GP bike, but a set of rollers or a drill starter would have fixed it. Hadn't really seen them back then. . . Circa 15 yrs back.

Being post 82 was the final nail and we don't do Bears up here really. Good chch bike.

You'd have been fit enough to push it back then Dave....
Went and looked at the SoT practise today. 3 New V4 Panigales...one being ridden by someone called Beaker...
No, not Tony Maxwell, I asked, LOL.

[F5 Dave]

Ha. Think he bought it of Maxwell

Yeah the 256 started just fine with a helper. On by yourself if you were energetic but if it failed you were stuffed. I arrived at a track day lineup sweating like Mike Tyson at a spelling bee.

I figured Holden etc always had an entourage to help.

[husaberg]

Ha. Think he bought it of Maxwell

Yeah the 256 started just fine with a helper. On by yourself if you were energetic but if it failed you were stuffed. I arrived at a track day lineup sweating like Mike Tyson at a spelling bee.

I figured Holden etc always had an entourage to help.

The old way for problem bikes was starter rollers and a 6 cylinder car.
the battery ones or the small engined ones were years later.
From memory the car was in reverse with the roller starter but Grump will remember
You needed a couple of strong lads to hold the bikke for the bit twins down while "Sheryl" reved the nuts of the VC Valiant wagon
Robert likely had more friends.

[F5 Dave]

Yeah seen those old school starters but just me in my van doing meetings it just wsnt going to work. Using TonyMacs starter at ruapuna was addictive. Foot on button drop clutch, pull it in move off. One person easy.

Nicest one was. . Memory. . . Budhas brother. . . Um, it'll annoy me, which one was Darryl, or Darren, ahh screw it but was made of ally treadplate and looked cool.

When at Paul's place couple of month back they used one of those lawn mower engines with a space saver size wheel contraptions to start the YZR . Again need a 2nd person.

[husaberg]

Yeah seen those old school starters but just me in my van doing meetings it just wsnt going to work. Using TonyMacs starter at ruapuna was addictive. Foot on button drop clutch, pull it in move off. One person easy.

Nicest one was. . Memory. . . Budhas brother. . . Um, it'll annoy me, which one was Darryl, or Darren, ahh screw it but was made of ally treadplate and looked cool.

When at Paul's place couple of month back they used one of those lawn mower engines with a space saver size wheel contraptions to start the YZR . Again need a 2nd person.

Darryl me thinks
Never met him but but i have an idea he do Alloy fab for a job.

[Grumph]

The nice stainless and treadplate ones are "Rosco" starters, originally made by an old neighbour of mine in Brighton, Ross Ennis.
His place was badly damaged in the quakes and I really must find out how he is now.
He gave up making them but his son who is/was a partner in a light engineering business in Oz took up the design and was selling them in Oz.
Ross had health probs and gave up racing too, haven't seen him for several years.
Last I heard, Ross got no royalties or cut from the ones sold in Oz...

I've fixed a couple of them in the past. Contemplated making one too. Never got around to it.
Big Rob locally has one ex Russell Bleach. Russ sold it cos it wasn't up to scratch. I went through it and found nothing.
The penny dropped eventually - it's a 24V version. Two batteries and it'll start most things.

Was at a SoT some years back with a customer bike which we were starting on rollers under his van. Britten was there for a demo.
Starting one of them from cold is probably the hardest job any set of powered rollers would be asked to do. The van struggled....

[jellywrestler]

Yeah ease of starting was a reason I didn't buy a mate's 256 Rotax GP bike, but a set of rollers or a drill starter would have fixed it. Hadn't really seen them back then. . . Circa 15 yrs back.

Being post 82 was the final nail and we don't do Bears up here really. Good chch bike.

you do need to get out more, there's bears at the Cemetery Circuit and this fine meeting into it's fourth year back up north from memory, although you may be meaning bucket bears, they don't do that anywhere.

[jellywrestler]

The penny dropped eventually - it's a 24V version.

sounds like the 1960's mate.....

[F5 Dave]

Oh, so two meetings, well I was completely wrong when I said 'really':rolleyes:

[Grumph]

sounds like the 1960's mate.....

Not really. The late small truck starters are visually identical to 12V car versions. This one I know was bought off trademe with very little info. A set of numbers stamped onto the motor body with no makers mark isn't much to go on...
Ross did actually do 24V versions to order. HD's and big twins on alky liked them.

To be fair to Dave, he's right in that the whole BEARS scene is a lifestyle choice down here. But that Rotax left ChCh because they also don't like 2 strokes...
From memory it was reclassified as F1.

[jellywrestler]

Oh, so two meetings, well I was completely wrong when I said 'really':rolleyes:

settle down, saw it as an opportunity to advertise the meeting, there's classes at other meetings to petal.

[husaberg]

To be fair to Dave, he's right in that the whole BEARS scene is a lifestyle choice down here. But that Rotax left ChCh because they also don't like 2 strokes...
From memory it was reclassified as F1.

Remember the hate that used to get poured on the chock chasers esp the two strokes.

But bugger Bears i think what NZ needs is a Single cylinder class just one rule it has to be single cylinder.
Split it in two classes 0-250 and open

[F5 Dave]

The owner told me erm. . Was it Dave Hicks, or another Dave who had it used to sandbag in 2nd place then fight for the lead at last lap. But if he made a mistake he catch it all up in a few corners. It got reclassified then I was told.

Heck I dunno Bears seems to be a bit redundant with S1000RRs and the like, but how could they stay in a time warp without being post classics?

I was interested as a pre82, for which the engine was 1980/81, but the chassis I found was 84 and they made first TZ ones 83. Shame.
With small cct mikunis I dynod it at 60hp with a sweet fat curve at very pedestrian revs. The rods were the weakness but bigger pin modifications could dramatically alter what safe revs could be achieved. Those barrels were super advanced for the time.

Anyhow, enough derailing if the thread with talk of the insensible twin. Still resides in a mate's spare room but my life took another path.

[husaberg]

The owner told me erm. . Was it Dave Hicks, or another Dave who had it used to sandbag in 2nd place then fight for the lead at last lap. But if he made a mistake he catch it all up in a few corners. It got reclassified then I was told.

Heck I dunno Bears seems to be a bit redundant with S1000RRs and the like, but how could they stay in a time warp without being post classics?

I was interested as a pre82, for which the engine was 1980/81, but the chassis I found was 84 and they made first TZ ones 83. Shame.
With small cct mikunis I dynod it at 60hp with a sweet fat curve at very pedestrian revs. The rods were the weakness but bigger pin modifications could dramatically alter what safe revs could be achieved. Those barrels were super advanced for the time.

Anyhow, enough derailing if the thread with talk of the insensible twin. Still resides in a mate's spare room but my life took another path.

There is a guy who can make Old style looking cylinders with RSW porting.
He offered to build some for Lozza on pitlane pretty cheap too. that 60 would be closer to 100HP

[F5 Dave]

Just safely raising the revs would take 60 to 70 all day long. Spigot mods and larger carbs, lose the Motosplat ignition- another jump.

[Michael Moore]

Greg, here's somethings from my files for the one-way clutch for a drill-powered starter attachment for 125/250 2T

"They were just a socket with the square end bored out and a mcmaster 2489K6 pressed in with a stepped shaft and a couple of snap rings to keep it all together."

https://www.mcmaster.com/2489k6

cheers,
Michael

[Grumph]

thanks Michael. I can't open that - my internet as usual - but it might help someone.

IMO, off the shelf locally trumps a potentially neater but harder to source solution....

[Michael Moore]

From the link, it appears to be a standard industrial part that your local bearing house can probably provide (or at least something similar to it):

One-Way Locking Needle-Roller Bearing Clutch
Single Row, Acetal Plastic Spring, for 3/4" Shaft Diameter
System of Measurement Inch
Bearing Type Roller
Roller Bearing Type Needle
Construction Single Row
Seal Type Open
For Shaft Type Round
For Shaft Diameter 3/4"
ID 0.75"
ID Tolerance -0.0005" to 0"
For Housing ID 1"
OD 1"
Min. OD Tolerance -0.001"
Maximum OD Tolerance 0"
Width 5/8"
Width Tolerance -0.01" to 0"
Ring Material Steel
Roller Material Steel
Cage Material Acetal Plastic
Spring Material Acetal Plastic
Maximum Speed 12,000 rpm
Maximum Torque 17 ft.-lbs.
Lubrication Required
For Shaft Surface Smoothness (Ra) 16 microinch
Shaft Mount Type Press Fit
Temperature Range -20° to 200° F
RoHS Compliant

The needles in these bearings roll freely in one direction, but lock to transmit torque when the rotation of the shaft is reversed. Also known as drawn-cup roller clutches. An arrow on the lip indicates the rotational direction that locks the bearings.

Single-row bearings do not support loads from any direction. To support radial loads, use with our Needle-Roller Bearings.

[Kickaha]

Darryl me thinks
Never met him but but i have an idea he do Alloy fab for a job.

Darryl, he's a coachbuilder, anything he builds is immaculate

[mr bucketracer]

is the The Sensible Twin finshed ?

[Grumph]

is the The Sensible Twin finshed ?

Believe me, I'm going like fuck on it Scott. Working at getting the roller finished before the ignition arrives.
Currently mounting a half fairing and the instruments. Tank is away being TIG'd - unlike you, I don't have TIG.

It's the little bits that hold you up. Into town today for more tubing, fasteners and vinyl for the number boards...

If the engine doesn't work out, at least I'll have a tidy roller which can take wider rims - and probably up to 100HP....

[Drew]

Haven't you got a couple cam stubs hanging out the side of the head? Cut a slot and taper the back side of said slot. Then put a handle on any car starter you can get your hand on.

Works for Yamaha MotoGP TEAMS.

[sidecar bob]

Haven't you got a couple cam stubs hanging out the side of the head? Cut a slot and taper the back side of said slot. Then put a handle on any car starter you can get your hand on.

Works for Yamaha MotoGP TEAMS.

Starting something through the camshaft? A world of pain on anything with a chain driven cam.
The tensioner side wasn't made for that kind of abuse.

[husaberg]

Starting something through the camshaft? A world of pain on anything with a chain driven cam.
The tensioner side wasn't made for that kind of abuse.

Even some gear ones have enough trouble with the valve gear remember the fibregear Holden 6's.
http://holdenpaedia.oldholden.com/images/thumb/2/27/Motor_and_seats_003.jpg/300px-Motor_and_seats_003.jpg
It took 25 old years for Honda to design a reliable tensioner as it was.

[Drew]

Just put the standard starter gear in and do it off that then.

[Grumph]

Just put the standard starter gear in and do it off that then.

Oh dear, silly me, that's the end of the crank I cut off......

Nah, drill will do it fine.

Chains being used to drive in both directions - starter/alternator drive chain on the GPZ900/ZX10/ZZR1100 kawasakis.
Started out about 12mm wide on the 900 - finished up about 20mm wide on the 1100. And the tensioner problems just got worse...
If the 1100 spat back on startup, it could rip the tensioner mech out of the sidecover.

[Grumph]

Grunty 3/8in drill on slow speed does it. 11.8 : 1 compression - you feel it when it's turning over.

Mounted instrument pack incl sorting what functions I want in the wiring. Which led to the realisation that the early sump I've used has a level sender and I want pressure warning...So I made up a double decker fitting for the banjo bolt on the front of the cases. It's on the end of a gallery direct from the pump and of course feeds the head galleries. Normal sender unit screwed on the outside and we're indicating.
As an aside, I found a nice piece of hex steel in the scrap box and used it for the extension - a Norton twin front cylinder head long nut. Never throw anything out....

I'll probably make up a stand for the thing tomorrow. I have a dedicated stand for each bike built. Then take it outside and maybe get some pics.
If we get some still days, there's a seat to paint too.

[mr bucketracer]

Believe me, I'm going like fuck on it Scott. Working at getting the roller finished before the ignition arrives.
Currently mounting a half fairing and the instruments. Tank is away being TIG'd - unlike you, I don't have TIG.

It's the little bits that hold you up. Into town today for more tubing, fasteners and vinyl for the number boards...

If the engine doesn't work out, at least I'll have a tidy roller which can take wider rims - and probably up to 100HP....not been here for a year after the germans took over

[Grumph]

not been here for a year after the germans took over

Your absence was noted. Good to see you back.

[husaberg]

not been here for a year after the germans took over


https://www.youtube.com/watch?v=iYdIXRTBXLo

[Grumph]

Where it's at right now. Still a lot to do. Probably the loom to make next.
Tank I may get back next week then the fittings to make.

Black wasn't my choice. Top fairing bought off trademe looked silver/gray in the pics...And the tinted screen, wasn't. However, it was cheapish.

Anyone got a rough tank cover from the early version ?

[husaberg]

Where it's at right now. Still a lot to do. Probably the loom to make next.
Tank I may get back next week then the fittings to make.

Black wasn't my choice. Top fairing bought off trademe looked silver/gray in the pics...And the tinted screen, wasn't. However, it was cheapish.

Anyone got a rough tank cover from the early version ?

That subframes a massive improvement, the old one looked like it was made of wrought iron. Looks Ducati, Still has pig iron lower yoke though.
So its a 3ln front end 38mm with the 320mm 2kr brake.

Pretty sure TZ had a big plastic bungs as per kart club rules

[F5 Dave]

I lost quite some Kilos from replacement ally tube on my YZF750SP subframe.

[Grumph]

I lost quite some Kilos from replacement ally tube on my YZF750SP subframe.

I cheated - it's silver paint. Still lots lighter than stock though.

Yes, Husa, it was covered in nylon when I got it. Racing on tracks shared with cars, common sense prevails and we don't need all the nylon. Now if only cars didn't drop oil....

[Grumph]

Right, I've got a working ignition. But an odd one. The new 2KR ignitor ex China has all the right colour wires but one don't work...

There's a blue wire which when power is switched on to the box is supposed to send power to the fuel pump relay. Turning the pump on.
It doesn't..I can live with this as it does at least spark. Means rewiring the fuel pump to eliminate the relay.

All the bells and whistles work - neutral and oil lights - even the temp gauge twitches.

So there's still the tank and fittings to do.....Then the carbs......

The ex NSR carbs are semi downdrafts. I've got to make the jet positions look like the pic in order to make them work in full downdraft mode.
I have some ideas. Subject to change without notice, LOL.

[husaberg]

Right, I've got a working ignition. But an odd one. The new 2KR ignitor ex China has all the right colour wires but one don't work...

There's a blue wire which when power is switched on to the box is supposed to send power to the fuel pump relay. Turning the pump on.
It doesn't..I can live with this as it does at least spark. Means rewiring the fuel pump to eliminate the relay.

All the bells and whistles work - neutral and oil lights - even the temp gauge twitches.

So there's still the tank and fittings to do.....Then the carbs......

The ex NSR carbs are semi downdrafts. I've got to make the jet positions look like the pic in order to make them work in full downdraft mode.
I have some ideas. Subject to change without notice, LOL.

That blue wire isnt part of the sidestand set up?
Blue on Honda is right indicator, i remember that from nearly thirty years ago.
Looking at a couple of Yamaha looms it seems to be ignition and park light tacho related so it might a engine is on power feed.
on the 400 loom it splices to blue and black and goes to the ignition switch looks like park and on.
https://www.classiccycles.org/media//DIR_1653304/DIR_1792956/7b4ebf4db60cffe5ffff81d3ffffe417.pdf
Looking further there is a lot of gubbins before it powers the relay for the fuel pump

[peewee]

Right, I've got a working ignition. But an odd one. The new 2KR ignitor ex China has all the right colour wires but one don't work...

There's a blue wire which when power is switched on to the box is supposed to send power to the fuel pump relay. Turning the pump on.
It doesn't..I can live with this as it does at least spark. Means rewiring the fuel pump to eliminate the relay.

All the bells and whistles work - neutral and oil lights - even the temp gauge twitches.

So there's still the tank and fittings to do.....Then the carbs......

The ex NSR carbs are semi downdrafts. I've got to make the jet positions look like the pic in order to make them work in full downdraft mode.
I have some ideas. Subject to change without notice, LOL.

would 28mm mikuni downdrafts work better than what you already have ?

[speedpro]

The blue fuel pump wire isn't switching ground instead of 12v is it? You don't have the standard carbs to try? What about a normal sidedraught feeding a plenum on the top of a couple of velocity stacks. Sort of like what I have but instead of the turbo feeding it have a carb. If it pops back it shouldn't be too big a bang.

[husaberg]

The blue fuel pump wire isn't switching ground instead of 12v is it? You don't have the standard carbs to try? What about a normal sidedraught feeding a plenum on the top of a couple of velocity stacks. Sort of like what I have but instead of the turbo feeding it have a carb. If it pops back it shouldn't be too big a bang.

He could just use a curved inlet.

https://www.youtube.com/watch?v=pxsRHqPF5os
https://www.youtube.com/watch?v=fOnwZup07aU
He fixed the crank by making a pressed up version

[Grumph]

I'm sure that what you put up is interesting Husa, please remember I can't see any youtube shit you post.

28mm Mikunis ? they'd have to be CV's - and no I won't even try CV's thanks. I'm actually quite experienced at setting them up - which means I don't want to. Which rules out stock carbs too - even if I have enough bits to build a pair. "Someone" - on the west coast i think - took a full set apart to see how they worked and I doubt I've got all the bits.

Ideally, I'd win lotto and order up a set of 4 keihins and split them. Don't like the odds of that.

To be honest, It'd probably be easier to convert a pair of Mk1 Amal concentrics to downdraft than these keihin semi downdraft flatslides.
The Dutch do it with Dellortos.

I'll check that the blue wire isn't switching ground as you suggest - but one of the dud boxes I have here will run the pump if you jiggle the exposed guts so i'm fairly confident i've got it right.

[husaberg]

I'm sure that what you put up is interesting Husa, please remember I can't see any youtube shit you post.

28mm Mikunis ? they'd have to be CV's - and no I won't even try CV's thanks. I'm actually quite experienced at setting them up - which means I don't want to. Which rules out stock carbs too - even if I have enough bits to build a pair. "Someone" - on the west coast i think - took a full set apart to see how they worked and I doubt I've got all the bits.
t.

Nah not here, one engine was from CHCH and the other from Dunedin way. one was $5 and the other $20 on trademe.
I had a third one on trademe in gisy but the guy refused to send it wheni got it for $1 on a no res Auction
All the carb and engine bits from me are how they were delivered. other than some rolling arround in my misses car.
The only thing removed was a conrod and a head and cover which either Neil or The hillbillies got, and a mag with Mike got. and odd bolts were robbed.
I looked at the carb box one day most of the bits seemed there.
from memory the two different engines had two sizes of intake ports.

Why cant you see videos Grumph
What the video is is Millyards engne with slightly curved intakes and PWK copy carbs.
341237

[Grumph]

I can't see videos because i'm on dialup. What life I have left isn't long enough to download anything.

Again, curved manifold are something I'm very familiar with - Aermacchis can be made to go very well with them.
If I can avoid it, I don't want to use tham here. I'm not just trying to get it running, it's a race engine.
As we all know, they're never easy...

[husaberg]

I can't see videos because i'm on dialup. What life I have left isn't long enough to download anything.

Again, curved manifold are something I'm very familiar with - Aermacchis can be made to go very well with them.
If I can avoid it, I don't want to use tham here. I'm not just trying to get it running, it's a race engine.
As we all know, they're never easy...

We all know the answer is then either Fi or TDM28mm mikunis FCR28's or Yoshimura 28 downdrafts.
341238341239
Rob priced the yoshi carbs
I emailed you the pic of Millyards its pretty short considering
I found a Chinese copy of the Yoshi downdraft carb but i cant find it now or for the last year.
https://wholesaler.alibaba.com/product-detail/Yoshimura-YD-MJN28-Dual-Stack-Carburettor_60783090638.html
there you go $68 USD each

the Downdrafts of the small TZR250 ikt would allow them to be shorter than the pwks plus they have all the 4T Mikuni stuff fits.
You coukd do the same with the Ta10's you have keep them at std angle and do a slight curved intake.
All Engines are compromises somewhere
that one one fires once every 4 strokes on each cylinder

[Grumph]

thank you for the Millyard pic. I'm pretty sure he's a mate of Allens the Mikuni agents in the UK. While they list Keihin sets for the FZR, they're much dearer than the Mikunis - and Allens primarily sell Mikunis. He's interested in simply getting it running properly, not racing it.

The Yosh carbs are again semi- downdrafts. I've looked hard at them to see what's different. It's the fuelling arrangements - not the mounting angles. 45 deg is apparently the max - and dellortos will do that.


I checked to see if the box was switching ground for the relay - no it's not. Nothing off that pin whatsoever. May not even be connected...

[peewee]

ive got a set of the mikunis but have no use for them pretty sure they were from some type of suzuki. rgv250 maybe but i dont know. if someone needs the them just pay the postage and theyre yours

[Grumph]

ive got a set of the mikunis but have no use for them pretty sure they were from some type of suzuki. rgv250 maybe but i dont know. if someone needs the them just pay the postage and theyre yours

Thanks for the offer. They're semi downdrafts like the Keihins I have. Between what I have here already in Amal, Dellorto and Keihin carbs - and what a mate has stashed away - I'm pretty sure I'll come up with something.

[husaberg]

Thanks for the offer. They're semi downdrafts like the Keihins I have. Between what I have here already in Amal, Dellorto and Keihin carbs - and what a mate has stashed away - I'm pretty sure I'll come up with something.

One of the GPs had no pilot jet at all didn't it?
How much angle do you need?
Suzuki Stinger like downdraft

[Grumph]

One of the GPs had no pilot jet at all didn't it?
How much angle do you need?
Suzuki Stinger like downdraft

No - the GP2 had the pilot relocated to the intake side so it's good for steep angles.

How much angle ? Measures up at 15 deg off vertical.

Funnily enough I have a pair of 90cc stinger downdraft carbs here...Bought years ago for pennies to see what the layout was.
No room to bore them though.

[husaberg]

No - the GP2 had the pilot relocated to the intake side so it's good for steep angles.

How much angle ? Measures up at 15 deg off vertical.

Funnily enough I have a pair of 90cc stinger downdraft carbs here...Bought years ago for pennies to see what the layout was.
No room to bore them though.

Yeah they were pretty tiny 18mm and 20mm or something the wolf was same casting but even smaller. wolf 90cc stinger 125 even same cylinders with thinner bores
IDA Weber is all i could think of unless you went smalll car like bambina or Ford MOCO escort. etc
the SP FZR400 had FCR carbs not sure what the inlets manifolds look like but i cant imagine they were steeper than 45 degrees

[Grumph]

Ok, still working...I'm going to give the keihins a try with this adapter. It's 15 degrees - which is 15 less than I'd like but 15 more than they are on the NSR. So 60 deg downdraft. I set the carbs up on the bench and worked out where the fuel level was at different angles. I think this will work.
Interesting to make. I'd made a parallel one in Tufnol and from that realised that I needed something I could tap into...
Got a mate to mill a chunk of alloy to a 15 deg wedge and basically hand cut it from there.
The carb rubbers are GS1000. Rock hard and useless until an overnight soak in Xylene. Magic.

Won't be able to try a fireup until a large item of UK origin leaves my work table.

[husaberg]

Ok, still working...I'm going to give the keihins a try with this adapter. It's 15 degrees - which is 15 less than I'd like but 15 more than they are on the NSR. So 60 deg downdraft. I set the carbs up on the bench and worked out where the fuel level was at different angles. I think this will work.
Interesting to make. I'd made a parallel one in Tufnol and from that realised that I needed something I could tap into...
Got a mate to mill a chunk of alloy to a 15 deg wedge and basically hand cut it from there.
The carb rubbers are GS1000. Rock hard and useless until an overnight soak in Xylene. Magic.

Won't be able to try a fireup until a large item of UK origin leaves my work table.

Paint thinners aye i thought thy would turn into a gooey mess?

[Grumph]

Paint thinners aye i thought thy would turn into a gooey mess?

Real rubber will. Pretty well all the carb rubbers are synthetic. Xylene is apparently one of the constituents.
My theory is that the rubber loses the light end solvents over time.
The good mixture is apparently Xylene and oil of wintergreen. Couldn't source wintergreen - methyl salicitate - in any quantity at an affordable price.
There used to be a guy - ex teacher - in ChCh who sold chemicals and equipment to schools and the public. Dead now I believe.
He was the only place to get a proper burette for measuring compression.

[HenryDorsetCase]

Thanks for the offer. They're semi downdrafts like the Keihins I have. Between what I have here already in Amal, Dellorto and Keihin carbs - and what a mate has stashed away - I'm pretty sure I'll come up with something.

clearly it's time to pull the throttle bodies off a wrecked Triumph 675 engine and go EFI!! The chaps at FE had EFI on a carbed Bonnie at one point.

[HenryDorsetCase]

Real rubber will. Pretty well all the carb rubbers are synthetic. Xylene is apparently one of the constituents.
My theory is that the rubber loses the light end solvents over time.
The good mixture is apparently Xylene and oil of wintergreen. Couldn't source wintergreen - methyl salicitate - in any quantity at an affordable price.
There used to be a guy - ex teacher - in ChCh who sold chemicals and equipment to schools and the public. Dead now I believe.
He was the only place to get a proper burette for measuring compression.

knowing that would have saved me a couple hundy if I had known it a couple months ago... inlet rubbers and carb to airbox rubbers ex DSS for the CB750... mine were off but like hell would they go on again.

[husaberg]

Real rubber will. Pretty well all the carb rubbers are synthetic. Xylene is apparently one of the constituents.
My theory is that the rubber loses the light end solvents over time.
The good mixture is apparently Xylene and oil of wintergreen. Couldn't source wintergreen - methyl salicitate - in any quantity at an affordable price.
There used to be a guy - ex teacher - in ChCh who sold chemicals and equipment to schools and the public. Dead now I believe.
He was the only place to get a proper burette for measuring compression.

I still have an old bottle of those tyre softeners they used to use on the karts (but never on proddy bikes). It always stunk of wintergreen.
Chemists used to be a good source of chemicals especially if they were owned by people that were interested in Motorsports.
Possible to get a lot of stuff now on the Net Trademe etc.
That said i do know a guy who is an industrial chemist who sells out of trade Email me.

[Grumph]

clearly it's time to pull the throttle bodies off a wrecked Triumph 675 engine and go EFI!! The chaps at FE had EFI on a carbed Bonnie at one point.

Nice in theory...but. Injection involves generating current which infers a working alternator. No thanks.
It also involves putting a cam position sensor on. Again no thanks.
I'm a great believer in the KISS principal for race bikes which only do short races...

I wouldn't use a Triumph anyway. Probably find a complete setup off a late 300 twin. Yamaha or Kawasaki.
I'll keep buying the lotto tickets.

[speedpro]

or - https://www.mikunioz.com/shop/mikuni-rubber-45-degree-mounting-manifold-sleeve-for-40mm-spigot/?v=8e3eb2c69a18.

I've bought bits of rubber hose from Supercheap at all sorts of odd angles and used that for manifolds. Some radiator hoses have all sorts of useful angles and come in lots of sizes. Usefully supercheap nearby used to have bins of radiator hoses I could search through.

[pete376403]

I bought a bottle of Oil of Wintergreen from www.lotusoils.co.nz - I used it to soften the airbox bellmouths on the GS1100. Considering they were rock hart before and only semi rock hard after I would call it successful .

[F5 Dave]

I've bought burette online from some supplier.

[Grumph]

It's a runner. No exclaimation marks as it was but a short burst. By myself, used the drill on the crank,wound the idle up a tad and full choke on unmodified NSR carbs. Shot of Start Ya Bastard down the 'oles and it went.
Couldn't run it for long as the carbs were leaking and I'd turned the fuel off. Couldn't try throttle as I had my hands full of drill...

Set the carbs up off the bike and the leaks are around the float chamber seam. Old hard O rings. They're currently soaking in Xylene...Why not ?
Eventually I'll probably have to buy a kit off Tyga but if this works....

Next time it's two people. One on the drill and me on the throttle to find out how far out the jetting is. It's got a sharp bark...

[F5 Dave]

Kewl stuff.

[TZ350]

It's a runner.

................:woohoo:

[Grumph]

Thanks but it was always going to be, LOL - It's just been hard fitting it in around other (paying...) stuff.
It's still going to be as and when i can fit it in, but as soon as I can get the tank back from the welder and finish things off so it's rideable, it'll be ridden.

One thing I looked at today was that I think the last person to ride that chassis was probably Avalon...So it's set up for someone half my weight.
Bit of suspension tweaking needed, LOL.

[husaberg]

One thing I looked at today was that I think the last person to ride that chassis was probably Avalon...So it's set up for someone half my weight.
Bit of suspension tweaking needed, LOL.

I never realised you were going to race it Greg?

Great stuff

[HenryDorsetCase]

Thanks but it was always going to be, LOL - It's just been hard fitting it in around other (paying...) stuff.
It's still going to be as and when i can fit it in, but as soon as I can get the tank back from the welder and finish things off so it's rideable, it'll be ridden.

One thing I looked at today was that I think the last person to ride that chassis was probably Avalon...So it's set up for someone half my weight.
Bit of suspension tweaking needed, LOL.

I see from her facebook that she is racing MX in the off season. She's a cool chick and has inspired a couple of women I know to give motorbikes a go, which is cool as fuck. They arent racing... but theres time.

[Grumph]

I never realised you were going to race it Greg?

Great stuff

Never say never, LOL. But I do have to test it to sort the carburation.
I try and ride everything that comes through the workshop.
As it's set up now, I'd reckon to hit the bumpstops a lot on the "private test track"

[husaberg]

Never say never, LOL. But I do have to test it to sort the carburation.
I try and ride everything that comes through the workshop.
As it's set up now, I'd reckon to hit the bumpstops a lot on the "private test track"

I am sure it cause you are far far taller old chap, rather than you just have hit the eggnog to hard.:msn-wink:

Carbs are amazingly sophisticated pieces of simple crude technology, in that its set up for a engine twice the size, one that also fires half as often, yet it still starts and likely will run also on the original settings.
it will be interesting to see if the FCR or PWK Needles fit.

[Grumph]

it will be interesting to see if the FCR or PWK Needles fit.

Don't have either in stock. Have tried for size everything here from VM's to old Honda CB Keihins to RS Mikunis.
They're an orphan length. They have very little taper at all so at least if it's lean on the needle, there's room to move.

[husaberg]

Don't have either in stock. Have tried for size everything here from VM's to old Honda CB Keihins to RS Mikunis.
They're an orphan length. They have very little taper at all so at least if it's lean on the needle, there's room to move.

Yeah a bit of sand paper and a vernier.
we used to use a unimat model lathe
http://www.glue-it.com/wp/wp-content/uploads/2016/03/unimat3-lathe-002.jpg
its amazing what people still pay for them but they used to do up to about 70mm
341790
never used the tool to trim just paper but you could set it up exactly where you wanted to thin out

[F5 Dave]

Bit of 80 grit on the battery drill ideally when you're drunk. :weird:

[Grumph]

Bit of 80 grit on the battery drill ideally when you're drunk. :weird:

Remember, I used to be the alcohol fuel guru for a lot of roadracers - won't be my first set of needles hand modified.

Going to reclaim the tank from the welder today and make some more bits for it.

[Grumph]

In town today and reclaimed the tank. Took the float bowls to Seal Imports Ltd - who supplied the correct O rings off the shelf for the bowl gasket...

At a total cost of $7.00 the pair.....Beats hell out of doing it on line, LOL. Not the first time they've come through for me. Highly recommended.

[Drew]

Seal imports are fucken awesome. They've had seals made for me before.

[husaberg]

In town today and reclaimed the tank. Took the float bowls to Seal Imports Ltd - who supplied the correct O rings off the shelf for the bowl gasket...

At a total cost of $7.00 the pair.....Beats hell out of doing it on line, LOL. Not the first time they've come through for me. Highly recommended.

Genuine 39 pounds on the fiche for one off a NSR including a tiny one for thefuel drain or something, a top gasket, plus the slide side gasket that's each FFS.

on the plus side the needle jet is replaceable this is about the same price which is at least a bit more resaonable.
the holder is also replaceable but only 2t
this is the pic from the early NSr from memory your carbs were either of a NS400 or NS250? is that right?
https://images.cmsnl.com/img/products/needle-setjet_medium16012KV3014-01_0045.jpg


oddly the similar carbs off the MVX250 seem to have very 4t PWK or other Keihin looking needle jets holder according to the pics in the fiche?
https://www.cmsnl.com/honda-mvx250f-1983-d_model50016/holder-needle-jet_16165438003/#.XNMcvY4zaUk

that also is the same part number as
CB1000C 1000 CUSTOM 1983 (D) USA
CB1100F 1983 (D) ITALY
CB1100F SUPER SPORT 1983 (D) USA
CB1100RBI AUSTRALIA (13MA3B24)
CB1100RBII FRANCE ENGLAND GERMANY NETHERLAND GENERAL EXPORT
CB1100RCII AUSTRALIA ENGLAND FRANCE GERMANY NETHERLANDS
CB1100RDII AUSTRALIA ENGLAND FRANCE GERMANY NETHERLANDS
CB650 1981 (B)
CB650 1981 (B) CANADA
CB650 1981 (B) USA

so its a 4 emulsion type holder at least on the MVX250.

Didnt drew have a bro or something with MVX parts?

looking a the NS250 fiche they are very generic looking holders and are emulsion type
https://blog-001.west.edge.storage-yahoo.jp/res/blog-53-91/asayan_nsr/folder/970937/93/28710993/img_1?1247501230

[Grumph]

They're MC16 type carbs. The first and simplest version without solenoid air bleeds - thank christ.
Nothing in them looks unusual. I'm quite capable of making jets incl the needle jet if it has to go leaner.
Float needles are good, they are in quite good nick generally.
All I've had to do is transfer the fuel inlet from the right to the left end of the fuel gallery.
That was easier than cutting a hole in the frame rail....

[husaberg]

They're MC16 type carbs. The first and simplest version without solenoid air bleeds - thank christ.
Nothing in them looks unusual. I'm quite capable of making jets incl the needle jet if it has to go leaner.
Float needles are good, they are in quite good nick generally.
All I've had to do is transfer the fuel inlet from the right to the left end of the fuel gallery.
That was easier than cutting a hole in the frame rail....

that one i posted first was MC16 as were the prices.
Bloody intersting the MVX has 4t parts in it.

[jellywrestler]

that one i posted first was MC16 as were the prices.
Bloody intersting the MVX has 4t parts in it.

about the only interesting thing about an MVX.....

[husaberg]

about the only interesting thing about an MVX.....

Nah its an unusal bike hamstrung by a weird decision to use cast iron cylinders and believe it or not head covers as well. As well as some other unusuaf borrowing parts from other bikes.
The balancing arrangement is also quite unusual, kind of like a twin balancing a heavy pistoned single its a corperste oddidy built just because of Freddie.
Far more common in NZ than anywhere else in the world i believe.

[Grumph]

Far more common in NZ than anywhere else in the world i believe.

Probably offered at a price Bluewing couldn't refuse - to get shot of remaining stock in Japan.
Wouldn't be the first - or last time - we were a dumping ground.

[jellywrestler]

Nah its an unusal bike hamstrung by a weird decision to use cast iron cylinders and believe it or not head covers as well. As well as some other unusuaf borrowing parts from other bikes.
The balancing arrangement is also quite unusual, kind of like a twin balancing a heavy pistoned single its a corperste oddidy built just because of Freddie.
Far more common in NZ than anywhere else in the world i believe.

story goes we got em cheap as they were destined for the crusher as they were so poor.
remember at the time they were approx $3454 the yammys were $4 and the rg gammas were $5400, vast difference between 3 x 250's really

[F5 Dave]

I remember the lines of them parked outside Sawyacomings and Honda Chitty. Buy a VF, get 2 of these thrown in or whatever.

[husaberg]

Probably offered at a price Bluewing couldn't refuse - to get shot of remaining stock in Japan.
Wouldn't be the first - or last time - we were a dumping ground.

Yeah like the GL145 and few others they were odballs but the MVX as far as i am aware was actually pretty popular in japan.
You can still get new cranks NOS for a 3K :first:


story goes we got em cheap as they were destined for the crusher as they were so poor.
remember at the time they were approx $3454 the yammys were $4 and the rg gammas were $5400, vast difference between 3 x 250's really


Honda were at the time letting a lot of young engineers loose. who were trying to use car techniques and less selective fitting and checking tolerances etc. My understanding was it wasnt successful at the time. :)
as they never had thr practical experiences of leaving margins for error.
there was also a production manufacturing war with Yamaha. as Yamaha were trying to be the biggest manufacturer that's why there was so many new models around then. From both.

[speedpro]

At Wanganui one year I was out for practice and following Jim Steadman on his TZ on my McIntosh. On the straight heading towards the pits, Jim blew past this guy on the right and I had him lined up on the left. He jumped left as Jim went past and I clipped him as I went past. I ended up going straight into the pit lane. Looking back all I saw was the bike cartwheeling down the road. It was the guys first ever road race. He ended up in hospital and I heard the bike was a write-off.
The bike was a MVX250.
The guys mates were not impressed with me and were keen to start a punchup in the pits.
The organisers had changed practice order but not everybody was informed. Me and Jim shouldn't have been practicing with the guy.

[Grumph]

Honda were at the time letting a lot of young engineers loose. who were trying to use car techniques and less selective fitting and checking tolerances etc. My understanding was it wasnt successful at the time. :)
as they never had thr practical experiences of leaving margins for error.
there was also a production manufacturing war with Yamaha. as Yamaha were trying to be the biggest manufacturer that's why there was so many new models around then. From both.

True - but Yamaha didn't make as many mistakes. What you say about production techniques is true. The VF's suffered at that time from exactly that. The cranks are badly finished - particularly the oil holes on the journals. They decided that simply running a linishing tape across the holes was sufficient. It isn't.
Every VF I saw with a big end that had picked up had sharp edges on the oil holes. A finishing step had been deleted IMO.
Even the RC30 suffers from this. I've shown the one here to the owner's rep who was a tad surprised. We assumed you were supposed to finish it properly before racing it.

[husaberg]

Even the RC30 suffers from this. I've shown the one here to the owner's rep who was a tad surprised. We assumed you were supposed to finish it properly before racing it.

Funnily enough TZ's reportedly were thrown together like this. Bell wrote a whole chapter on writing the wrongs of the TZ quality control.Probably yamaha never made as many mistakes as honda in the early 80's, but theyre were still some bikes of the ilk, XZ550
Generations of starter clutch's on others, but at least Yamaha could built a decent camchain tensioner and a cam that didn't eat itself ot weld itself to the head.
Yamaha also never took the chances Honda did or introduced the production intonations like the non seperate cylinders etc.
but with the yamaha farm bikes there were some howlers like the splined rear disc, hondas splines on the rear axel was quality control from the yanks, but Yamaha's disc was a silly design

[dangerous]

but the MVX as far as i am aware was actually pretty popular in japan.
You can still get new cranks NOS for a 3K :first:

Not much good if ya cant get pistons tho :eek:


. The VF's suffered at that time from exactly that. The cranks are badly finished - particularly the oil holes on the journals.
Even the RC30 suffers from this.

correct me if im wrong... but only the VF750 ever had an isue, never ever heard of a 4,5 or thour doing this and certnly never a RC30 which is in the VFR family bullet proof and over engineered eg: a 86 750 I had with 240k on it and never touched...


Yamaha could built a decent cam chain tensioner

yeah well hondas issue there was simply that the auto tensioners only adjusted so far, the chains were still perfect nick... eg I did 3 in a 500EC Hondas parts depo was thriving well LOL

[jellywrestler]

Not much good if ya cant get pistons tho :eek:



correct me if im wrong... but only the VF750 ever had an isue, never ever heard of a 4,5 or thour doing this and certnly never a RC30 which is in the VFR family bullet proof and over engineered eg: a 86 750 I had with 240k on it and never touched...



yeah well hondas issue there was simply that the auto tensioners only adjusted so far, the chains were still perfect nick... eg I did 3 in a 500EC Hondas parts depo was thriving well LOL

i thought it was a bad batch of vf500's where they didn't chamfer the oil holes in the crank were particularly bad, the early shaft drive sabres had issues with cams? and the vf 750's cooked in the six hour races as when they turned off for gas they overheated, most went about two to three laps and died except the one where they had bypassed the fan and run it off the battery direct.
didn't help that the barrells were cast into the top crankcase not like normal bikes....

[husaberg]

Not much good if ya cant get pistons tho :eek:

correct me if im wrong... but only the VF750 ever had an isue, never ever heard of a 4,5 or thour doing this and certnly never a RC30 which is in the VFR family bullet proof and over engineered eg: a 86 750 I had with 240k on it and never touched...
yeah well hondas issue there was simply that the auto tensioners only adjusted so far, the chains were still perfect nick... eg I did 3 in a 500EC Hondas parts depo was thriving well LOL

RC30's exploded all over the track in the first year i cant rememeber why but maybe as it was not an dual endfeed crank
Its posted in the RC30 thread from the TWR?
https://www.kiwibiker.co.nz/forums/showthread.php/185387-RC30-What-does-this-mean?p=1131094352#post1131094352

Honda in the early 80's introduced a system of tighter machining and put together any parts but the parts manufacturing wasn't accurate enough for a start off.
They also had a lot of new designs with minimal R&D plus some buggars never serviced them properly or changed the oil.

[Drew]

Greg tells me that Honda are just cunts for making bearing tolerances too tight anyway.

[Grumph]

Greg tells me that Honda are just cunts for making bearing tolerances too tight anyway.

This is basically true - up till recently anyway. The first CBR600 I pulled down (first version) had been run in carefully and raced once prior to being gone through.
The bigends were just on the point of smearing, oil was carbonised on the back of the shells. The mains measured up at less than a thou clearance.
It got cleaned up and reshelled with the thinnest shells in the range. Became a byword down here for speed and longevity.

Of the V4's...I've seen personally 400's (VFR's and NC30's) 500's and 750's which have done bigends. In every case, hand on pacemaker, the crank was badly finished. The first two NC30's raced in ChCh both did bigends very quickly. Fixed them both, luckily VF400 shells fitted and the cranks weren't damaged.

Dangerous, if you're out this way, come and look at an RC30 crank. Might change your opinion.

[AllanB]

Probably offered at a price Bluewing couldn't refuse - to get shot of remaining stock in Japan.
Wouldn't be the first - or last time - we were a dumping ground.


Suzuki have been doing that for ages with Summer Fest and started before that was a thing with those IL4 Impulse bikes in the 80's - NZ could.t get enough of them!

[F5 Dave]

DR400S
GB400/500
FT400
GL400
XZ400
MVX250
XT400
VFR700
LS400
NV400
Impact/Repulsive 400
RG400

And so forth

[husaberg]

DR400S
GB400/500
FT400
GL400
XZ400
MVX250
XT400
VFR700
LS400
NV400
Impact/Repulsive 400
RG400

And so forth
Are you saying some of the RG400's came in new? i thought assumed they were all jap imports
The 700's were american models as there was a tariff to protect Harley on over 700cc bikes.

[F5 Dave]

Hmm, I remember a couple of the lads had RGs. Were they new? Not sure now you mention it. The others were.

[Grumph]

Are you saying some of the RG400's came in new? i thought assumed they were all jap imports
The 700's were american models as there was a tariff to protect Harley on over 700cc bikes.

Some of the 400's did come in new. Enough to have the Junior production class capacity for 2T's go up to 410 from memory. The Yamaha guys welcomed that and the RD400's too.
Never seen a US market 700 here though I'm told some did come.

The twin when tried with a second person showed it was achingly lean. Hand over the carbs got a response.
So I've been in with the drills working from previous flatslide experience.
If it's fine this weekend I may move things around and have another try.

The tank went to another welder. It's ready to collect but an hour away - so next week.

[husaberg]

Some of the 400's did come in new. Enough to have the Junior production class capacity for 2T's go up to 410 from memory. The Yamaha guys welcomed that and the RD400's too.
Never seen a US market 700 here though I'm told some did come.

The twin when tried with a second person showed it was achingly lean. Hand over the carbs got a response.
So I've been in with the drills working from previous flatslide experience.
If it's fine this weekend I may move things around and have another try.

The tank went to another welder. It's ready to collect but an hour away - so next week.

There was another 400 CL400? i cant remember but it was high piped and late 80's.
the 400s were popular as there was a massive jump in rego and insurance after 400cc in Japan i think.
Amazing its lean? half the size and half as often half the power but i guess half the airflow to draw out the fuel as well.

[AllanB]

We got a load of ex Japan new in NZ 400's in the 80's, overstocked in Japan, unloaded in NZ for a good price. The above list is very true, GB Hondas, XV Yammys all sorts of bikes. I remember the first load of bikes being about $3500 new, sold out almost overnight and the next load had a 'dealer' increase of a few hundy, the last touched $3999.

Moving forward to the early 2000's Suzuki Summer Fest the GS1200ss arrived shit cheap. Next shipment and random box opening exposed bikes with titanium Yoshi headers and alloy cans - dealers paid the same but quickly threw on a few hundred 'extra' for the Yoshi equipped bikes. I owned a Yoshi equipped machine - the headers were quite beautiful, perfect slip fit and fantastic exhaust note.

[Grumph]

A day of tanks. had to move the taps on a steel tank for a bike I have here. Different motor, carbs in a different place, taps fouled carb tops.
So machined up bosses and welded them in. Time flies.

Anyway, got the filler cap neck glued and rivetted in on the bucket tank.
Mounts are : a rubber pad on the frame, a 10mm rod through a rubber bushed crosstube in the tank - registering with the subframe mounts, and a yet to be made rubber bushed mount off the subframe in front of the seat.
Tank's roughly 6 litres. Height in the pic is deceptive - top of filler is only about 100mm above seat level.

It'll have to run a pump as about half the tank capacity is below the carbs.

[husaberg]

A day of tanks. had to move the taps on a steel tank for a bike I have here. Different motor, carbs in a different place, taps fouled carb tops.
So machined up bosses and welded them in. Time flies.

Anyway, got the filler cap neck glued and rivetted in on the bucket tank.
Mounts are : a rubber pad on the frame, a 10mm rod through a rubber bushed crosstube in the tank - registering with the subframe mounts, and a yet to be made rubber bushed mount off the subframe in front of the seat.
Tank's roughly 6 litres. Height in the pic is deceptive - top of filler is only about 100mm above seat level.

It'll have to run a pump as about half the tank capacity is below the carbs.

Rocker cover cap as per GPR it s neat trick.
I just know you want to set up the fuel pump with a rockermon the swingarm like a JPS or a works G45.
That said why cant you use a pulse pump like a Outboard or kart of the crankcase pressure.

[Kickaha]

That said why cant you use a pulse pump like a Outboard or kart of the crankcase pressure.

You need to run a regulator and return line, a Yamaha pump with built in regulator would be far better

[Grumph]

You need to run a regulator and return line, a Yamaha pump with built in regulator would be far better

Already have an FZR250 pump and filter. Bulky and heavy but simple.
The fitting on the tank top is actually for a breather. as the cap was originally an oil filler, it seals pretty well.

[Grumph]

Rocker cover cap as per GPR it s neat trick.
I just know you want to set up the fuel pump with a rockermon the swingarm like a JPS or a works G45.
That said why cant you use a pulse pump like a Outboard or kart of the crankcase pressure.

Already answered - but given the small cylinder size, intake pulses would be IMO too small.
Crankcase volume fluctuations again would be barely noticeable - the cases are actually a bigger volume than OE with half the crank missing, LOL.

[husaberg]

Already answered - but given the small cylinder size, intake pulses would be IMO too small.
Crankcase volume fluctuations again would be barely noticeable - the cases are actually a bigger volume than OE with half the crank missing, LOL.

Two true i forgot got the other 2 cylnders cases there as well.
The Harleys and some of the kart clone Chinese Hondas have pumper tilitsons on them harleys obviously have small cases large cylinders as a V twin but the clones don't.
I wonder if thats an option if you cant get the Kehins to work properly the pumpers work at any angle
https://www.arcracing.com/hl-334wx-carburetor-ec-tillotson/

That said whats wrong with rocker pump on the swingarm or are your tracks are too smooth over their.:whistle:
I cant remember what you were going to run Total loss electrics?

[speedpro]

Not many wires on your one

[Grumph]

Yeah, total loss electrics. Only ignition and pump to power. And yes, as we're only running on the big tracks a swingarm pump isn't really feasible.

Was at a meeting a month or so ago where the dirt karts ran. Didn't notice any pumper carbs - most now seem to have gone to injection on the Lifans.
When I can open that link I'll have a look. Didn't know 4T pumpers were available.

[Grumph]

Not many wires on your one

If you're referring to Husa's (cough) long term project, I've yet to see any....

Mine, harness is reasonably simple. As befits an elderly builder, LOL.
And, no, I'm not available to trouble shoot yours, sorry.

[husaberg]

If you're referring to Husa's (cough) long term project, I've yet to see any....

Mine, harness is reasonably simple. As befits an elderly builder, LOL.
And, no, I'm not available to trouble shoot yours, sorry.

It would be funnier if both of you weren't using parts from husaberg.
But i took it as being compered to Mikes it has buggar all wires. Besides Its Dave job to poke fun at me.

I actually tripped over the NSR125 the other day.

[Grumph]

It does have some wiring Mike. 4mm alloy plate used to mount battery box lower outside, ignition box upper, outside. Coils are stacked on inner side.
Seemed like a good way to use the space. Battery is low, forward and accessible.

[Grumph]

I actually tripped over the NSR125 the other day.

Sell it immediately on OSH grounds....

[husaberg]

Sell it immediately on OSH grounds....

Its funny how well that engine fits in that frame:innocent:

[jellywrestler]

Rocker cover cap as per GPR it s neat trick.
I just know you want to set up the fuel pump with a rockermon the swingarm like a JPS or a works G45.
That said why cant you use a pulse pump like a Outboard or kart of the crankcase pressure.

or off the exhaust pipe blow by...

[husaberg]

or off the exhaust pipe blow by...

Hey?...........

[Grumph]

The stars have aligned and it's back on the bench with work resuming...

An early FZR250 tank cover was purchased pre xmas - rough, dented and badly sprayed bleck Ideal...It's been trimmed radically and hinged at the front. A rubber band at the back, rubber channel glued around the bottom and i'm happy with the look.

[Grumph]

Well, FTW. The site's timing me out after a short paragraph, autosave isn't working and it won't let me edit a post.

Lots more has been done but you won't hear about it.

[sidecar bob]

Well, FTW. The site's timing me out after a short paragraph, autosave isn't working and it won't let me edit a post.

Lots more has been done but you won't hear about it.

When you log in, go to the top & click in the box that says "remember me" I think that's what it says, I haven't logged out for years.
It also may be down to the hamster out your way getting tired of running the internet generator wheel, or have you upgraded to the steam powered internet now?

[jellywrestler]

Hey?...........

instead of using vacuum from inlet manifold tap into the exhaust pipe and the pulse from that will drive a fuel pump

[sidecar bob]

instead of using vacuum from inlet manifold tap into the exhaust pipe and the pulse from that will drive a fuel pump

You were sidecar racing in the '80's wernt you.

[husaberg]

instead of using vacuum from inlet manifold tap into the exhaust pipe and the pulse from that will drive a fuel pump

The safari tank on my sons WR250 does that using the inlet to drain the "Wings" and pump it back to the main tank.
Plenty of 2T's use the intake pules for outboards and Chainsaws.
I don't recall one on a exhaust other than i think some 2t RC pylon planes?

[Grumph]

When you log in, go to the top & click in the box that says "remember me" I think that's what it says, I haven't logged out for years.
It also may be down to the hamster out your way getting tired of running the internet generator wheel, or have you upgraded to the steam powered internet now?

It's not the sign-in - or the hamster. The incompatibility between vodafone dialup and spark ultratrick is such that the site sees the delays as faults and shuts me out. We have the same prob with trademe - but it comes up and tells you why it's shut you down. Middle of this year we should be upgrading.

Until recently I could edit posts. Now i can't. I'm having no probs on overseas forums - but I assume spark didn't spend the money on making their system compatible with everything in use in NZ. They expect you to have the latest programmes.

[jellywrestler]

The safari tank on my sons WR250 does that using the inlet to drain the "Wings" and pump it back to the main tank.
Plenty of 2T's use the intake pules for outboards and Chainsaws.
I don't recall one on a exhaust other than i think some 2t RC pylon planes?

steve roberts did this on the plastic fantastic

[speedpro]

People may not know but thanks to Grumph's generosity I now have his bike. I've actually had it for a while but have only recently made sufficient progress on my own twin to feel comfortable starting work on The Sensible Twin. There's still a bit of work on my own bike so first up I'm just sorting out appearances. Sanding most of the black off and tidying up the front fairing which I'll start on tomorrow. So far I've only got the primer on. A bit of bog tomorrow to fill in a few holes, sanding, a bit more primer, and it'll be ready for it's coat of Kawasaki Green paint. Sorry Greg.

[F5 Dave]

Or you could change your name to Mike Black and save the effort?

[speedpro]

Taa-Daaa, all green

[F5 Dave]

It's a little known 'fact'that early Yamaha race bikes were painted the same shade of lime green. . . . (I do all my fact checking on alt reality conspiracy websites).

[husaberg]

353074353075

[speedpro]

I got a new tin of green paint. It's a custom colour based on my original FZR twin which was painted "Kelly Green". It turns out there are more than a few different "Kawasaki Greens" in the database. If it ever gets to that I might just choose one so I can replace it easily rather than having to match each time

[pete376403]

I got a new tin of green paint. It's a custom colour based on my original FZR twin which was painted "Kelly Green". It turns out there are more than a few different "Kawasaki Greens" in the database. If it ever gets to that I might just choose one so I can replace it easily rather than having to match each time

Mazda have a green ( Mazda2 Spirited Green Metallic 36A) that is a very close match for my 08 KLR, which is slightly metallic. The 72 F9 that I had was extremely close to Terex earthmover green.

[diesel pig]

(I do all my fact checking on alt reality conspiracy websites).

The only place to get the Good oil on our secret reptilian overlords.

[speedpro]

The sensible twin has made it to the garage where work sometimes happens. Plugs have been pulled so I can spin it over and check for spark. It doesn't spin easily. It's hard enough that I doubt I can spin it and check for spark at the same time. One lead disconnected from it's coil but that was the cylinder that looked like it had been running. Currently I have a couple of standard carbs plugged in. I know they work, just not very well. One has a slightly sticky slide. I'll have to borrow a kart starter from my mate. I should be able to turn it over with that and check for spark at the same time.

[Grumph]

It's got a fair bit of compression but I was spinning it with a 2-speed 3/8 drill. How's it feel turning the outside flywheel by hand ?

[speedpro]

It runs OK with stock carbs. It blips OK considering at least one slide is a bit sticky.

The ease with which I could start it with the kart starter has convinced me to modify my alternator cover to allow the same thing on my motor. I have no idea why I haven't done it before.

https://www.youtube.com/watch?v=S9ZiAJhiIDE

[Grumph]

Well done. Still got the cam cover leak ?

[speedpro]

Not sure. There is a slight leak but my suspicion is that it is from the area around the left crankcase cover plate. I need to run it for a bit longer and really clean it first.

[Grumph]

Not sure. There is a slight leak but my suspicion is that it is from the area around the left crankcase cover plate. I need to run it for a bit longer and really clean it first.

One of the things I didn't get round to was a couple of dummy cam caps that the side plate could be screwed to. No positive clamping on the plate above barrel level. Suspect it isn't flat enough to seal on the cam cover end.

[husaberg]

tyga list them for arround 65usd.

https://litetek.co/Carb_Kit_Yamaha_FZR250_2KR.html
https://litetek.co/Carb_Kit_Yamaha_FZR250_3LN1.html


https://tyga-performance.com/product_info.php?products_id=5080

[speedpro]

The sensible twin has a new home. I've been tied up with my other projects including my son's 600 now. Getting the sensible twin on track was looking less and less likely which was disappointing. Hopefully it won't be too long until we see it on track now.