Pete's TF125 build

[F5 Dave]

Well here's just a quick build to try and produce something raceable from something that looked pretty but was not. Pete saw the pics of the Orange NSR on Tardme and bought in faith.

When it arrived from Auckland clearly all was not well. In no order, the brakes were useless, the crazy big rear tyre made it handle like a truck, it was also offset to one side to get it to clear the chain. Uh Duh!

Supposedly the bike was faster than a warm FXR. Clearly that was a lie. The bike had never been raced I'd guess and the clutch slipped so bad it was a joke. And it vibrated.

Engine out and in my garage. Clearly everything ignition, carb, and mostly the porting were stock. The crank looked rebuilt and supposedly it has a TS gearbox in it which provides better ratios. We'll be checking that obviously, but there is a spare bottom end and that is a TS.

So the plan is to build a petrol push and ride engine for my good mate Pete that will give him the 2stroke fix he desires and be more competitive than his mostly stock FXRAGH. It will want to be grunty as it has to pull his, er. . . manly carcass about the track.

I decided we weren't going to stray into too much development. Just built with good parts which allow more power through good engineering.

At this point I'd like to thank our benefactor TZ350 who super generously sent some GP clutch parts, an RGV250 rodkit and all manner of odds and sods for the build. As well as some good ideas. GPs have an extra clutch plate and the inner basket swaps over. The outer basket has a different gear and matching gear doesn't fit the crank.
But the basket was better with less slop so I swapped them over and helicoiled the rivet holes and bolted together with lots of studlock.

[mr bucketracer]

Poor Mr g...

[F5 Dave]

After much adoo deciding what parts to hold it together with and with some ideas and measurements of parts TZ had laying around I decided to run the RGV rod and a YZ125 Wiseco piston.(we part number) It needed a rebore as there was a clear groove from the old ring where it must have rusted to the bore. I bought a longer hollow big end pin as the RGV one was a bit short. I also bought a Proper RGV bearing as the kit was aftermarket and the bearing a cheaper non flat cage design. Pjme in UK carry them cheap and post cheap once you email them.

The 80s YZ piston is much better than the 70s TF one and flat top with 1mm ring.

[F5 Dave]

This will be a work in progress
Look at the cool bag the piston comes in!

[Akzle]

fucken pete .

[F5 Dave]

Getting ready for the game.


Bwahahaha

Just kidding don't give a fuk about sweaty men playing a kids game.

Milled reed block to a more RM or RG angle.will cut barrel to suit.

[F5 Dave]

fucken pete .

We're good mates but never crossed that barrier.

However a little wine. Some smooth music. You never know.

[timg]

Cool. I'll be watching progress with interest. :rockon:

[F5 Dave]

And more pics

Here are some heads. Dreadful offset plug. Also I can't machine with a central mandrel. This one is non squish so needs some weld.

[F5 Dave]

OK the piston is much shorter. Means the intake timing is 200 degrees. Way too radical. I'll fill the bottom of the port to reduce this.

Makes the ports too small. But I can now move the port roof up. Usually you can't do this but the piston is much shorter.

Here's the old crap piston.

Line is where the new piston lives.

[F5 Dave]

The pipes a bit shit so we'll see what we can do.

We'll run 196 and 129 which should see it OK. Try for 185 inlet after I fill the bottoms of the ports.

So we've ordered an ignitech and will run a lifan stator as shown in TZs thread.

38hp? Sure why not?


or maybe 1\2 that. :confused:

[F5 Dave]

So we're going to run .35 carbon on the reeds. The crank has been bored out to 22mm from 19mm which means we can run a better rod and it will be a more rigid crank.

The 1mm ring will flutter at much high revs than the snoozoki meaning better cooling and less power loss through fluttering.

[speedpro]

I ran my TS intake at 200deg by dropping the port down, not for the full width. Maybe 60% of the original port width. I also ditched the reed valve and devconned the hole in the bottom of the port where it used to be which made a nice flowing intake port. My thoughts were that the reed valve was only ever going to be used when the motor was revved beyond what the piston port duration was good for, taking into account resonance and such. Had 200 degrees exhaust as well and probably ran compression at about 14.7:1. It only made 19.9hp but it was a huge fat 19.9hp. Not tooo bad 25 years ago. With what we know now about ports I still wouldn't change the intake on that motor. The exhaust port I might change but only at the exit to the pipe. The transfer angles I did change but didn't go far enough at the time.

[F5 Dave]

Yeah I remembered your intake and devcon reed area. I'll try the 1/2 reed version, its only running a 24mm carb and I got it working well on the RG. I did consider cutting rear off and reedvalving it. Transfers staying completely std. This will hopefully be a low effort build making power from some sensible part choices.

[F5 Dave]

The crank has been bored out to take a 22mm pin. This allows the RGV rod and also should give some added rigidity to the crank as it pounds up and down, hopefully reducing vibration as a nice side effect. Some meat has been taken from the pin area to give more clearance for thicker rod and race clearance plus opening one balance hole should help the vibration point be moved to a non race rev area.

These bikes live their life at about 5000rpm chasing chooks or dragging Baabra up to the top paddock to do whatever farmers do in the top paddock.

[speedpro]

Balance was the BIG thing I forgot to mention. You need to reduce the balance factor. I did it by pressing a slug of aluminium into each of larger holes in each crank wheel. If your crank is anything like mine you will have a hole in each web each side of the crankpin. One hole is larger than the other. Opening a balance hole will INCREASE the balance factor which is opposite to what is required.

With weeks between sessions on Pete Sales dyno, inbetween which I pressed in the slugs, Pete commented immediately after the first rev of the motor about something being different. It is really obvious the difference.

The bike also went from breaking brackets, chambers, and even the frame through vibration to being nearly turbine like at revs.

[F5 Dave]

Ohhkay. Funny with the MB on your advice I followed the path of boring holes either side of the pin which really helped. I guessed the same way but was surprised to see such large holes there. Hmm. Maybe I should build a jig. Or maybe just push some ally in the hole.

[speedpro]

The MB "had" a balance shaft which added to the crank balance factor in the direction of piston motion and subtracted from it at 90deg to piston motion.

The TS has no balance shaft and as you have already mentioned the TS motor is tuned and balanced for it's intended purpose of creeping around the farm, at lowish revs. With any such motor the balance factor needs to be reduced if you are repurposing it and will be operating it at elevated rpm. Remember that the reciprocating forces increase proportional to speed whereas the revolving forces increase with the square of speed. You just have to change things so that the 2 lines intersect at the rpm you want, probably about 11,000rpm now versus 5,000rpm originally. With all the factors affecting the feel at the end including chassis/engine geometry there's no point getting too technical. Suck it and see, just push the alloy in, it will work.

[F5 Dave]

Roger Roger. Thanks forgot about the balance shaft.

[FastFred]

... just push the alloy in, it will work.

Pretty much what Rick Ford did. Worked Ok.

[Moooools]

Remember that the reciprocating forces increase proportional to speed whereas the revolving forces increase with the square of speed. You just have to change things so that the 2 lines intersect at the rpm you want

Happy to be shown I am wrong here (and apologies for dragging this off track), but my understanding is that this is a common misconception. All of the motions of masses are made up of sinusoids. The rotating crank is just the a mass moving back and forth and up and down sinusoidal 90* out of phase. The piston moves up and down with the sum of the big end height added the effective conrod length - as these are added (and therefore of the same units) and not multiplied/divided, there is no way that a factor of crankshaft speed is going to drop out of the mix.

It is my contention that the vibration 'sweet spot' that bikes have is due to harmonics in the bike/engine system. Changing the balance factor changes the directions and amplitudes of imbalance forces and so excite different harmonics in the bike at different RPM points.

[F5 Dave]

Thanks Mike you may have saved me going the wrong direction. Crank is just being finished so will push in some ally tonight.

[TZ350]

It is my contention that the vibration 'sweet spot' that bikes have is due to harmonics in the bike/engine system. Changing the balance factor changes the directions and amplitudes of imbalance forces and so excite different harmonics in the bike at different RPM points.

Perfect explanation of why one size does not fit all and you have to find the best balance factor that suits your bike by trial and error.

[F5 Dave]

I seem to recall you bored the holes bigger in the GP cranks. Pretty hard to search these days. Or did you fill those too?

The MB was OK without the balance until you revved it a bit more. With holes bored by pin it went to being buzzy at race speed to - a bit annoying in the pits (4000 blipping) but good on the track.

[speedpro]

All of the motions of masses are made up of sinusoids. The rotating crank is just the a mass moving back and forth and up and down sinusoidal 90* out of phase.

When you combine 2 sine waves that are 90* out of phase, as when 2 signals are combined on an oscilloscope, the resultant is a circle. Forget that the crankshaft is a crankshaft and consider it to be a rotating mass with an extra lump on one side. Calculate the force generated by that lump at a certain rpm and then calculate the force at double the rpm. The basic formula to use is something like F=(mv*v)/r. V squared but I don't know how to get a proper "squared" sign. V is the tangenital velocity of the mass concerned so double the rpm = doubles the V, which is squared.



It is my contention that the vibration 'sweet spot' that bikes have is due to harmonics in the bike/engine system. Changing the balance factor changes the directions and amplitudes of imbalance forces and so excite different harmonics in the bike at different RPM points.

Changing the balance factor does not change the direction of imbalance forces. Taking the whole engine /chassis package and changing the engine balance will alter perception of the imbalance. Vibration in one plane is more irritating than vibration in an other.

[F5 Dave]

I just got home and decided to weigh the std cast piston vs the prolite forged .5mm o/s piston.

180g suzook
185g wiseco

Measured on my rickety scales, I have good ones at work but the fact is the amount of bananas is very similar.

Did some porting with long reach carbide burr. Very hard not to get terrible vibration but with air drive can almost be controlled and stops quickly. Finished the inlet ports off with stones and sanding bits to get it smooth as I care to. Ie straight and not rough.

Inlet ports are much higher and biggerer affording me some scope to fill the bottom of the ports, then I'll do final area measure and timing measure.

I cut the manifold mounting area off and will make a plate the new manifold can bolt to which will be welded on a little and gap filled with JB Weld..

Tonight I'll space the barrel to get the transfers right and measure the ex which I only roughly raised but got scared and need to measure properly. The new rod is longer so I'll need to make a spacer once its in.

[Moooools]

When you combine 2 sine waves that are 90* out of phase, as when 2 signals are combined on an oscilloscope, the resultant is a circle. Forget that the crankshaft is a crankshaft and consider it to be a rotating mass with an extra lump on one side. Calculate the force generated by that lump at a certain rpm and then calculate the force at double the rpm. The basic formula to use is something like F=(mv*v)/r. V squared but I don't know how to get a proper "squared" sign. V is the tangenital velocity of the mass concerned so double the rpm = doubles the V, which is squared.

Changing the balance factor does not change the direction of imbalance forces. Taking the whole engine /chassis package and changing the engine balance will alter perception of the imbalance. Vibration in one plane is more irritating than vibration in an other.

Very aware that two sine waves 90* out make a circle. I was using that description to help illustrate the point that both the piston and the crank imbalances rise with the square of crankshaft RPM. I wasn't very clear there sorry.

Two graphs below. The first shows the imbalance force inline with the piston throughout a cycle at varying RPM Each line is an increase of 1000 RPM (poorly labeled). Note the shape remains constant and the magnitude increases by the square of RPM.

Second graph is the angle of the imbalance force with varying balance factor. This one is labeled a bit better, and shows the angle changing for different balance factors.

Graphs made from a first-principles derivation of crankshaft forces. Engine specs 54mm stroke, 100g piston, 150g con-rod, 100mm con-rod, 100g big end weight of con-rod.

Very apologetic for dragging this thread down Dave. I will give it a rest now.

[F5 Dave]

Set the barrel to where the transfers will end up. Measured that 4mm on the inlet floor would take me to 185 inlet. Cleaned and centre punched some keys in the floor and warmed up the barrel and resin. Turned the old piston upsidedown and set it to 4mm up, flowed some resin to about right and left to set.

I'd also checked the ex duration. Well, only another 3.4mm to raise the roof to get to my hardly radical 196*. Sheesh! Remeasured that a few times.

I'd like to meet who. . . `ported' . . .this and ask what they were expecting. Sure had spent a bit of time getting the duct shiny.

[speedpro]

Sounds like a mud bug or whatever cylinder. There was a version that had real low exhaust port. The shame is that it probably had the same oversize exit port to the pipe.

I'd forgotten about the angle of the imbalance force. Suzuki probably didn't when they made the TS cranks as the holes on either side of the crank pin are different sizes. Possibly to counteract this. I don't have the maths to calculate it.

[TZ350]

I seem to recall you bored the holes bigger in the GP cranks. Pretty hard to search these days. Or did you fill those too?

Balance holes ether side of the big end pin on a GP crank are different sizes to each other too and the balance holes are bigger in diameter than the TF/TS crank.

331567

GP crank on the left, TF/TS crank on the right.

After plugging with alloy and boring the 19mm big end pin hole for a 22mm (solid) pin we had to use a slug of Mallory (pure Tungsten) metal opposite the BE to get the balance factor for the GP about 50-55%

331566

The TF/TS crank wheels are thicker than the GP ones and their holes are smaller too. So their counter balance weight is proportionally much heavier than the GP. I suspect you can plug TF/TS balance holes with alloy and use a solid BE pin without needing to correct the BF with Mallory metal slugs.

A whole lot of posts by Thomas on Balancing a single cylinder crank.

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1129267538#post1129267538

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1129267785#post1129267785

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1129267718#post1129267718

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1129269584#post1129269584

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1129364519#post1129364519

You can tickle up the balance factor when the crank is re assembled by drilling shallow holes where needed, see the drill press picture in the post below.

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1129934876#post1129934876

Work carefully and you wont get any dirt in the BE and if you do it washes out easily enough with a squirt from a spray can of CRC.

[F5 Dave]

Kewl.

Had to take a skim off the weights as rod I beam is 1mm thicker and could just touch. Hollow be pin. Pressing slugs in and think we'll try it. So many variables from std setup.

All the heads offend me so original plan to just run it may morph to welding the centre plug head and then I can machine a squish head. We'll see how Pete's money to pay for outside work holds up.

Ignitechs are supposedly on the way and we're going to get gst etc slowing things up. Ordered some wires from UK to make up looms which split by 5 people made them $20 each for decent think walled auto wire.

Oh yeah. JB weld pushed into the tiny ex bridge holes of the piston. See if it lasts as well as TZs Benzonwhatever stuff.

[TZ350]

Had to take a skim off the weights as rod I beam is 1mm thicker and could just touch.

Yes, forgot to mention it, we take 1mm off the inside of each crank face and also something off the thrust washer area as the RGV rod BE is thicker and bigger than the GP.


Oh yeah. JB weld pushed into the tiny ex bridge holes of the piston. See if it lasts as well as TZs Benzonwhatever stuff.

JB weld should be fine, if not it won't be the end of the world. I would use JB, no problems, if I can't blag some more of the super trick stuff from Darren.

[Farmaken]

I built up a couple of straight plug heads by welding and machining but could never get rid of all the porosity in the welds from the crappy parent material.
Bored a head and shrink fitted an insert and instantly got rid of a heap of detonation.

[F5 Dave]

Yeah I lost an mb50 head the same way but I'm hoping just doing the squish area will be OK.

[F5 Dave]

I'll put some pics here of the inlet port. resin looks good and a light tickle should get it even. I might end up drooping the edges where the piston comes down further (the middle is shorter) o that corner bit that hasn't flowed to the edge will drop down anyway.

[F5 Dave]

Here's the cut reedblock. As you can see it will need some matching and filling a bit but all this is positive.

Then the back of the skirt will be trimmed to aim flow above the crank rather than into the crank gap.

I'll need to fill some area below the reedblock as it takes up less room.

I also need a way to hold the block to the barrel so it doesn't fall off. Think I'll drill some pegs in the sides and use the std screws to retain and bond in place so can't come out.

[F5 Dave]

Reed block still needs mounting solution but I had some time when the kids were awake to do some noisy stuff. Back of skirt trimmed. Bore to transfers blended. Will need another tickle after a bore.

[F5 Dave]

Exhaust raised and widened. Not my best work and still need final measure and clean up. Pig of a bent port to work in.

[F5 Dave]

Here's the crank. Needs to go in and thinking about making a stuffer to fill area below smaller reed block. Might screw it in place.

[speedpro]

I'm thinking that filling both holes in each web might be a step too far, depending of course on just how hard you are going to rev it. Based purely on my own experience. You going to blow the swarf out before assembling it?
The gas flow in my TS exhaust port used to do a 360 twist in the length of the exhaust port going by the carbon deposits. Real odd but it went OK at the time.

[F5 Dave]

Well first off we bored the 2nd hole out the same as the first so filing it redressed that error, also aiming for like 12,000 peak power with a bit of run on, which with a flat cage bearing, bigger pin and better piston than the Suzuki fare should be reliable. I hope.

[F5 Dave]

Well Pete came around last night so we could get a few things crossed off the list. Got the reed valve cut out of carbon sheet. . .


Drank some beers in the garage. . . :drinknsin

Packed it in at 2am. Maybe I'd be more productive doing it by myself :pinch:

[F5 Dave]

Made a spacer plate for under the reed area answer a barrel spacer to make up for the longer rod. These things always take longer than expected.
Need to bolt the reed spacer. One side only. Then can assemble bottom end.

Sorted a new inlet manifold.

Barrel should be back from rebore next week and can do a final measure. Getting the plate welded on for manifold but will be sealed with JB Weld. Couldn't be a build without copious resin.

Getting a squish band built up on the hemisphere head. Hopefully it doesn't turn to bubbles.

Carb it std but aim to taper it out on the engine side at later date.

[F5 Dave]

Crank in. Ready for clutch. Barrel still not back from bore.

[speedpro]

8mm nut under the head of the 6mm bolt, only in bucket racing is this perfectly acceptable on a race engine.

[F5 Dave]

Ha! Well spotted. Actually they all have nuts there. I used some bolts to pull the cases together evenly but they got too long once pulled in. I'll fit the JIS std screws next.

[F5 Dave]

Grr I mutha humping hate those stoopid snoozookie clutch springs. What the heck is wrong with a few simple screws like everyone else?!??

My puller is too thick. Think I'll make a tiewire attachment.

Not shown: correct screws fitted in other side.

Robs donated GP clutch basket with 1 more plate than TF.

[speedpro]

Grr I mutha humping hate those stoopid snoozookie clutch springs. What the heck is wrong with a few simple screws like everyone else?!??

My puller is too thick. Think I'll make a tiewire attachment.

I made a nice one from a piece of 8mm rod. Filed the end into a narrow hook and had a hole through the other end for a screwdriver to be used as a handle. Somebody needed it more than me.

[F5 Dave]

S'funny I never had this much drama with my old TS I put into an RG frame. Actually I think it was your RG frame. Maybe I had a better pull tool back then. Not sure where it came from but. . .
Just kiddin.

[TZ350]

Grr I mutha humping hate those stoopid snoozookie clutch springs. What the heck is wrong with a few simple screws like everyone else?!??

I feel your pain.

A Suzuki GN125 clutch inner has screws and looks like it might fit. I am going to try one on my GP100.

332175

The GN clutch. 6 plates. The GN splines are the same as the GP and TF.

332177332176332178

[F5 Dave]

Well the tie wire worked, but that was 1\2 hr of concentration and fiddly placement that I'll never get back.

Side cover on. Just check the clutch. . . and it's locked solid! Puller pulls side cover on. But no further. Oh, right. The extra plate means the puller is now a few mm closer. Bet the GP one is shorter. Either I hunt in the spares or put a spacer behind it. . realisation. . and have to take off that friggin plate to swap it :weep:

Time to give up. Made a couple of base gaskets and glued up the kick starter hole. Bah!

[F5 Dave]

Ahh, I see. They're a pushy type like the RG rather than a pully type like, erm the TS. Spacer it is.

[F5 Dave]

Hmm. Still no dice. Wtf!

OK measures; pressure plate seems to virtually touch the cover.

Pete shows up with TS cover. Nope the same.

Ahh. TF pressure plate different from the TS (and GP)

Why? Surely a different plate and different basket are more expensive to develop produce separate runs and maintain stock control for the 1 clutch plate saved?!??

Mucho easier to fit clutch spring pins with 2 people. Edit; and now I think about it about 5mm less preload.

[F5 Dave]

Right last job tonight. I'll fit the stator plate. Hmm. Baseplate diameter bigger but some filing at the mounts could fix that. But wires stop it sitting flush.

See the wires at 9 o'clock.


Will have to consult Robs pictures of the swap before I move wires and cut grooves.

Then this gets bored to fit this in it.

[Muciek]

Flywheel seems very small , from what's bike it is?

Wysłane z mojego Redmi 4A przy użyciu Tapatalka

[FastFred]

Hmm. Baseplate diameter bigger but some filing at the mounts could fix that. But wires stop it sitting flush.

HMmmm, I think TZ forgot to point out they remove the stater core and pickup then turn down the OD of the stater plate and shift the wires underneath when re assembling it.

[F5 Dave]

Cool thought that could be the go but wanted to check as seemed strange not mentioned.

And it's from a Lifan pit bike of some sort. As long as it provides enough juice for the ignitech and a pulse it's fit for porpoise.

Original Suzuki ones were ideal for a farm bike but shear the crank off when asked to do 12000.

[TZ350]

I think TZ forgot to point out they turn down the OD of the stater plate.

True that....

332318

The bottom three coils circled are the 12Volt generator coils and give about 2A (25W) which is enough for an Ignitec's 1.5A draw at full song. The top two coils are high Voltage for charging a CDI's capacitor. We strip those two poles and sometimes re wind the three bare poles with more 12Volt windings for extra current capacity.

The winding sequence is tricky, it goes clockwise then anti clockwise then clockwise again or the other way round can't remember but easy enough to work out if you look for it.

If I was doing another one where I wound extra 12Volt wingdings I would bring out two sets of wires, one pair from the new windings and the other pair from the original windings and run two separate cheep Chinese 12Volt voltage rectifier/regulators. Hard to balance the new windings with the original, much easier to run two 12Volt voltage rectifier/regulators with their 12Volts output wired in parallel.

[Drew]

Isn't balancing it just a matter of having the same length of wire on each?

[F5 Dave]

Of the 3 coils to the 2 coils. Yeah two rec regs is a good idea, but I'll just run the bottom 3 and one for now and measure for volt drop at full chat. Thanks Rob.

[TZ350]

I'll just run the bottom 3 and one for now and measure for volt drop at full chat.

I think that will be all you will need. Measuring for Voltage drop at full chat, that is a better idea than my effort of revving it up with a 25W light bulb.

[husaberg]

Cool thought that could be the go but wanted to check as seemed strange not mentioned.

And it's from a Lifan pit bike of some sort. As long as it provides enough juice for the ignitech and a pulse it's fit for porpoise.

Original Suzuki ones were ideal for a farm bike but shear the crank off when asked to do 12000.

What method are you using to piece together the flywheel?
i was having a nosey the other day at brake and clutch rivets
Those suzis sure have a real shallow long taper

[TZ350]

332321332322

As well as using lock-tight on the screws I also glued the rotor parts together with 5min Araldite, 5min because it stays a little flexible and wont crack off like super strength does.

[F5 Dave]

On my bikes, The CR stator into a decent size cap with a Chinese rec/reg had no drop over the battery terminals when run up on the dyno. The battery is not used except when bike off and PC connected.

Hopefully the TF /Lifan can prove as steady. You only need as much as you need. The MB runs a fairly hungry intercooler water pump, carb solenoid, quick shifter, knock gauge, shift light. The TF has none of that. Actually will get shifter and light but that's squat and instant.

[F5 Dave]

Barrel back. 5mm plate and .7mm gasket.
196 ex
128 try
183 in
That'll do.

[F5 Dave]

So hemisphere head and now flat piston. I tell weldy guy; try best you can to build it up. Skim it flat and scoop a bit out to see not too porous. I'll cut the dome.


This is how it came back. I spent 2min with some sandpaper.
Yet to measure it. Bet he's fluked the cc. Pretty happy.

[FastFred]

That is very good welding work, very impressed.

[F5 Dave]

Yeah he said you have to burn out the rubbish bit at a time. Surprisingly the bowl looks a decent depth and he had a cutter he made when doing a KTM insert.
Karl at Cemeck in Petone. He's a tool maker that welds as sideline but somehow is talented off trade .

[Drew]

Yeah he said you have to burn out the rubbish bit at a time. Surprisingly the bowl looks a decent depth and he had a cutter he made when doing a KTM insert.
Karl at Cemeck in Petone. He's a tool maker that welds as sideline but somehow is talented off trade .
Ah, the penny drops. That fella is a master with the metal.

His spark erosion trickery is sick. Every Kawasaki owner should visit him with gearbox in hand.

Mind. With the little material being removed from the drive dogs, grinding doesn't actually ruin the tempered steel.

[F5 Dave]

barrel o-ring. Viton 144.
Carb taper adapter.
Flywheel bored out.

[F5 Dave]

Stator plate
I filed about 1mm on each mounting point. Then inwards so the bolts fitted (not shown). Can't adjust it but that suits me for ease of reassembly. Adjustable in Sw.

So I pulled the wires out the back of the plate and rerouted them and added an earth wire.

I also had to grind the case and cover a little to clear the pulsar coil.

[TZ350]

Great looking progress. :drinknsin

[rgvbaz]

Great thread :)

I race a X7 so similar weird intake and i'm looking at what would be better - as is or just piston ported with the reed tunnel filled?

I do have a question: Where are the boost (C ports) fed from? Is it from the B port transfer tunnel?

Cheers

Dave

[F5 Dave]

Yes my RG50 was the same. Actually works okish. Fed from Bs. There must be people who have tried piston port on X7s. But figured the reed will help on shorter tracks getting out of corners. Do flatten up the reed block. I did the TS piston trick in my x7 to about 275cc but it was a roadbike not sure on your rules. The same issues affect x7s. Mediocre parts which is why the cranks are weak. If you are allowed the same sort of crank mods and modern pistons will slow many more revs. Getting rid of that silly head gasket and cutting the head in half will cure failures there.

[rgvbaz]

Yes my RG50 was the same. Actually works okish. Fed from Bs. There must be people who have tried piston port on X7s. But figured the reed will help on shorter tracks getting out of corners. Do flatten up the reed block. I did the TS piston trick in my x7 to about 275cc but it was a roadbike not sure on your rules. The same issues affect x7s. Mediocre parts which is why the cranks are weak. If you are allowed the same sort of crank mods and modern pistons will slow many more revs. Getting rid of that silly head gasket and cutting the head in half will cure failures there.

Cheers for that Dave.

What do you mean by flatten up the reed block?

I did test steel std reeds against some hy-tech fiber reeds (that are years old) and there was a little difference but not much. I also want to make a blank so I can do some runs with the reed blanked off as i'm curious to see how it benefits the curve

332488

Max is a 1.5mm overbore. Is the ts 56mm?

Crank is something for the winter... not had any failure yet but peak power is at 9 - 9.5 k. Also I run a total loss ignition so only a small trigger on the end of the crank.

Head gasket is gone... it came spigoted :) though considering going the lapped and doweled route to get more contact area with the cylinder for better cooling of the head.

Cheers

Dave

[TZ350]

What do you mean by flatten up the reed block?

Max is a 1.5mm overbore. Is the ts 56mm?

Suzuki TS125 is 56mm bore standard.

Attached from Cooker race products tuning tips for a RG50 is the section on the flattened reed block.

[F5 Dave]

Pain to do back to back tests with reeds where they are. If you can get the revs up and you should you may have to revise the reeds again. Carbon sheet is easy to work but always test. I've reverted to steel more than once.
Bury yourself in parts diagrams and find a decent piston and rod combination presumably from mx aftermarket. Flat cage bearings available from pjme in UK. Perhaps a place to consider for rod mods.

Thin ring pistons cope with revs and shed heat better than flapping thick rings.

Peak at 11 should be possible with better rods and bigger crank pins. More places are capable of the accuracy machining these days. Power would jump considerably with pipes adjusted and ideally ports.

I swapped GS (550 etc) front caliper to improve brakes. Also used longer shocks but sure that's well trodden path.

[rgvbaz]

Suzuki TS125 is 56mm bore standard.

Attached from Cooker race products tuning tips for a RG50 is the section on the flattened reed block.


That's great info - thanks

Note - the pipes I have made were designed with Graham Coker's exhaust pipe calculator.

[rgvbaz]

Pain to do back to back tests with reeds where they are. If you can get the revs up and you should you may have to revise the reeds again. Carbon sheet is easy to work but always test. I've reverted to steel more than once.
Bury yourself in parts diagrams and find a decent piston and rod combination presumably from mx aftermarket. Flat cage bearings available from pjme in UK. Perhaps a place to consider for rod mods.

Thin ring pistons cope with revs and shed heat better than flapping thick rings.

Peak at 11 should be possible with better rods and bigger crank pins. More places are capable of the accuracy machining these days. Power would jump considerably with pipes adjusted and ideally ports.

I swapped GS (550 etc) front caliper to improve brakes. Also used longer shocks but sure that's well trodden path.

Yep - back to back is a pain... the last test was 1hr 15 mins between tests (me stick changing reeds over). I have some carbon sheet and Dat2T says the frequency is a much better match than the steel or fiber...

Yes the std 19mm crank pin and 14mm piston pin isn't great for piston/rod choice. I'll look at options on the Grampian site and maybe splash out this off-season and upgrade the crank.

I run a AP classic front brake caliper and race EBC pads - the braking is pretty damn good :)


Cheers again for the great info

Dave

[F5 Dave]

Yeah so perhaps TZR or YZ rods matched to YZ piston. Oh hold on, piston port. Check out Strike KT pistons oversized go fair high. But crank small end.

Maybe CR pistons around 54mm. . or RM.

Anyway chances are you can find something.

[speedpro]

I'll just mention it due to what has been said above. My thoughts were that the reeds extend the top end revs of the standard engine with the small piston ports. At all other times it simply hinders flow in the intake port. If you time the piston port for the revs you want then there is no requirement for the reed and you can fill it in and make a nice intake port.

[rgvbaz]

Yeah so perhaps TZR or YZ rods matched to YZ piston. Oh hold on, piston port. Check out Strike KT pistons oversized go fair high. But crank small end.

Maybe CR pistons around 54mm. . or RM.

Anyway chances are you can find something.

I had a look and a RM rod is 15mm piston pin and 22 crank pin (pin is 3mm longer though... Will they machine?) It's 10mm longer rod too which in theory should help.

Piston wise - 00-03 RM and 05-08 CR pistons look best and have the ring pin at the rear. Overall length is shorter than the x7s 60mm piston (RM 57.25mm and CR 59mm) but I want to experiment with inlet timing on the std piston with a file on the rear skirt first to see what she likes...

Cheers

Dave

[rgvbaz]

I'll just mention it due to what has been said above. My thoughts were that the reeds extend the top end revs of the standard engine with the small piston ports. At all other times it simply hinders flow in the intake port. If you time the piston port for the revs you want then there is no requirement for the reed and you can fill it in and make a nice intake port.

Agreed and something I'd like to try.

I'll find the X7 tuning thread that is on here and post some X7 stuff on there and stop de-railing this one.

Once again - thanks for the input.

Cheers

Dave

[F5 Dave]

I had a look and a RM rod is 15mm piston pin and 22 crank pin (pin is 3mm longer though... Will they machine?) It's 10mm longer rod too which in theory should help.

Piston wise - 00-03 RM and 05-08 CR pistons look best and have the ring pin at the rear. Overall length is shorter than the x7s 60mm piston (RM 57.25mm and CR 59mm) but I want to experiment with inlet timing on the std piston with a file on the rear skirt first to see what she likes...

Cheers

Dave
Shorter piston you can file inlets upwards. As long as it covers the ex port and shouldn't be an issue. Yes you can grind pin shorter. Shorter pin to crown is nice if you can get it. Obviously you have to check port timings and deck once its all together and fettle. Rebore will tend to lower transfers say 1/2 - 1 degree and ex not at all

[speedpro]

Pin will be able to be machined. Finish with grinding. Mate machines tool steel, with the right inserts, and you don't want to be too close when the chips are flying.

[F5 Dave]

Reed block mounted. Sideways screw captive with washer and bolt. Loctite and then resin.

[F5 Dave]

Squish squished.

That's plenty tight. I might pop the head off after a few runs to check the piston crown. Should be fine.

[F5 Dave]

Kinda all nailed together
Just drill and tap stator and my job is done.
Well then it'll be finished all the other jobs on the chassis that won't have been finished and the loom even though as a sparky he should be better able than me.
Then set up ignitech and do some tuning runs on the Dyno.

Might be able to get back to doing my 496 before summer.
Except this bloody GSXR. Should finish the Stinger too.
Dirt bike muffler needs a repack.
So does the 675.
Heck there's probably stuff to do around the property.
I need a lifestyle sponsor.

[Muciek]

Could You tell me what is the OD of the magneto? I have found 2 versions one is 88mm and is slightly different , 2nd looks like Yours but they didn't included the diameter in specs, and they not in the mood for measuring... Thanks

[FastFred]

Could You tell me what is the OD of the magneto? ... Thanks

OD of magneto flywheel rotor is 78mm.

332560

[F5 Dave]

Ran outta time to measure it before work but FF got that one.

[F5 Dave]

Engine is in but spent most time fixing other shit like swingarm.

Still has the 160 on rear. Sigh.

[mr bucketracer]

you need that 160 for all that power it will put out

[F5 Dave]

:laugh::laugh::laugh:

[mr bucketracer]

what power have you got from this beast

[F5 Dave]

At the calculator or at the rear wheel.

0.0 in both cases.

Engine is zipped together just needs wiring finished but that is with Pete and I'm working on wiring my 496. And dirtbike maintenance. We're off down south next week with the lads so another week on no garage progress.

[F5 Dave]

Good grief. Coming up on a year since last update where it sat In Pete's garage largely untouched. OK so last week he bolted the pipe on.
Back in mine on Sunday.
Throttle cable made. Clutch cable sorted. Sprocket fitted properly.
Wiring mostly complete. Battery for setup then will sort charging is working.

Pc talks to cdi. Sparks using test.

Rotor tapped to new inner and fitted with studlock aplenty.

Just rubs on backplate screws so may need to move that back a mm or two then can spin and see if it sees the pickup and can try starting it.

[F5 Dave]

Not that keen on the pipe that came with it but will do for testing. RS125 in the wings.

Wheels of course unchanged. Guess that will be up to me as well.

[TZ350]

.
Looking Good ........ :2thumbsup

[F5 Dave]

Cheers Rob. I assume the Lifan to TF rotor has same spacing as GP so odd that it rubs a bit. Did you have to shave yours back a bit?

[TZ350]

Cheers Rob. I assume the Lifan to TF rotor has same spacing as GP so odd that it rubs a bit. Did you have to shave yours back a bit?

No, not the flywheel and I too would have thought things would be much the same.

I do remember that some stater plates were relived on the back in the main bearing oil seal area so they would sit down flat and the outside diameter turned down a bit so they would fit inside the original GP cases but we worked on a lot of different units so I cant remember the specifics of the Lifan stater plate mod but yours could easily be hanging up on the oil seal, check that and also try skimming a couple of mill of the back of the stater plate.

[F5 Dave]

No, not the flywheel and I too would have thought things would be much the same.

I do remember that some stater plates were relived on the back in the main bearing oil seal area so they would sit down flat and the outside diameter turned down a bit so they would fit inside the original GP cases but we worked on a lot of different units so I cant remember the specifics of the Lifan stater plate mod but yours could easily be hanging up on the oil seal, check that and also try skimming a couple of mill of the back of the stater plate.

Think I did the oil seal but will recheck. Had to do the outer pretty sure. May just need to spot those other take to work on the mill.

Doing a garage night tonight with Pete. Last time we didn't even get the bike off the trailer but bike is in garage so maybe we should be on task. In between rigorous testing of beverages. Quality assurance begins at home.

[F5 Dave]

We'll it runs not 1/2 An hr ago (like 1.30am). Short test ride in the driveway. Let clutch out, pull it in 10 feet later, rev bike a few times turn it off. Sweet!

We may have a drunken little. But very nice beer.

[TZ350]

Great ....... :banana:

[F5 Dave]

Yeah tried to start it on the stand a couple of times but got all excited and opened the garage door. Did evaluate the situation and decided not to get near the road as we'd moved onto the 8% beers some while back. In fact with Pete's car in drive we had about a car length to start it and 1/2 To stop it before the back of the van.

1st time it barked into life.

I've marked 10, 15, 20 degrees on the flywhee (on some tape using a degree wheel)l vs a blued line on the stator. Next we'll run it up with the strobe light. If it shows closer to 20 retard it a few degrees on the Ignitech base advance. Currently it has a 15deg flat line. That way at any revs it should line up. Then we can get it near the dyno and adjust.

Also trailed in the 3.5" rear wheel. Some new bearing will convert 17 to 20mm axle. Just spacers now.

[Rick 52]

Top work, sounds exciting :)

[F5 Dave]

Had a few minutes so decided to set the timing correctly. Caught the 11,000 RPM rev limiter and the flat line curve had reset to some odd curve. All you need to do is change the bike inputs and it scrambles previous settings.

Sadly I had the stator too far out and 40deg base setting wasn't enough to get it on spot. Can't move plate so will have to broach another slot on the flywheel and try it all again. I could just run it without the key, but that is giving a problem for the future when has to be set up with degree wheel and all that palavour. Kneedit in the old slot. Always does my head working out which way to go as you add move base advance to get it closer but position actually needs to be retarded. Gaah.

[F5 Dave]

Ok ignition flywheel recut slot. Bang on, 14 degrees is adjusted to 15.
Charged my old alarm battery as not sure if alternator wiring is right.

Took it to the dyno, which sadly I'll lose access to end of the year after like 20 yrs.

Std jetting 18.7hp. Oops left the choke on. Oh much worse. 107 mj. Sheesh. Won't pull a 150. 132 it will but only 16. Everything after gets shitty. Hmm, measure battery when running, about 6v. Crap, no point continuing, wait check alternator. 43VAC. Sweet will need go wire that up to the rectifier and a cap.

Lot of stuff loose. This thing was badly built by that Auckland liar he bought it off.

Oh, and even with the ex raised about 4mm peak power is about 9500. So actually peak that low is surprisingly high. Another 2500 should make some decent go, maybe bodge my RS125 pipe on it. Still well above the 15 hp his FXR with pipe and carb made.

[F5 Dave]

Well we didn't manage to raise it much. Maybe near 19.

Ah there was supposed to be a picture but didn't load try again later.

[lodgernz]

Squish squished.

That's plenty tight. I might pop the head off after a few runs to check the piston crown. Should be fine.

Dave, I thought it was best to have the solder parallel with the gudgeon pin, i.e. east/west. Your photo (I think) has it north/south.
Wouldn't that have a piston rocking error?

[F5 Dave]

It should reduce that. Results seem to come out even when you measure both, so it seems to work. Maybe on bigger piston but I've not struck that. Ideally you check all 4 corners at some stage to see your head face is plain on the plane.

[F5 Dave]

We popped in on the Buckets last Sunday after a ride and it has motivated Pete. He has spent weekend in the shed getting it ready for a looong overdue shakedown run. Probably aptly named as the crank balance factor isnt right I'm pretty sure. We didn't measure it, just took Mike's suggestions.

Thinking back he ran both as a 100 and a 125 in bigger clubmans class. Didn't ask if 125 shook more.

Either way need to then graft RS pipe onto it as it is revving like a farm bike..

[F5 Dave]

Well shakedown run. A year after it was finished just needing nylon etc to be track ready.

End of the day the bike still runs, so that's a win.

The biggest issue was he found it super uncomfortable on his knees. The pegs are too far forward, too high and the seat unit makes all this worse. We moved the seat up with some stiff cardboard box jammed under the front. So far so bucket.

Then it stopped. Flurry of activity, rerouting fuel lines, oh, no spark, add a battery, spark comes back, won't start. change plug , no. Hmm. Bit of oil at the base gasket. . . And 3 of the 6 nuts missing. Add those and it starts. We'd never retorqued them and with a thick ally spacer and vibration they loosened off.

Big list of ergonomic changes and need for new pipe.

[speedpro]

.... the crank balance factor isnt right I'm pretty sure. We didn't measure it, just took Mike's suggestions........Either way need to then graft RS pipe onto it as it is revving like a farm bike..

the little adjustment I used worked a treat at racing revs but was a bit rough at farm bike speeds. Take it for a thrash before too much worrying.

[F5 Dave]

Well I took the experience from dyno reving it out. My MB was spot on with 10mm holes you suggested. Vibes uncomfortably in the pits, fine to race. Pete actually said the same but hes only really touching 10500 perhaps and was worrying about other stuff like sore knees.

I've invented a high tech spring puller in my head. Just need to get my wood saw and screws out to make it. You'll larf, but I think it will work great.

[F5 Dave]

Well

Cut a coil and half off the clutch springs with dremel cut off disc. This means I can wind them in further for 2mm more preload and also reduce the active springs giving an 11% increase in rate.

This will make the tricky arrangement a pig to put together. Enter new spring tool. Let's see if i can reattach this. Larf you might.

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=344519&d=1580702734

[TZ350]

Enter new spring tool. Let's see if i can reattach this. Larf you might.

https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=344519&d=1580702734

Not Larfing, looks good. Looks like it will make the job much easier with good control of lifting the springs and holding them up so you can slide the pin in. Great job. I think it is very clever.

[F5 Dave]

It was version 3 in my mind. The other versions all potentially rotated the spring when I tested them (whilst trying to get back to sleep).

[speedpro]

Didn't laugh but a little snort did escape. It always amazed me how far the pins could fly if the spring escaped before the pin was fully in place.

[F5 Dave]

Well finally got the cut down clutch springs in. Took a fair bit of concentration and two sets of hands but the tool was well worthwhile. Probably hampered by the state we were in by then. Made a longer gear rod out of some hex rod ,to match his rather simple rearset adapter plates. Flat plate a bit thin for my liking but we'll see.

I then broke my LH m6 tap by running it into the rod hole on the lathe which was way too shallow.
Not paying attention for afore mentioned reason.

Pipe will go to Damon to modify the header I think so it actually gets done. RS pipe should wake it up quite somewhat. As will a clutch that now feels less like a Trials bike and more like a racebike just on effort to pull.