TS125 Powered Bucket

[jthespanner]

Hello Lads and Ladess's

I have recently built a new bucket bike specs as follows.

1989 GSXR250 (GJ72) frame
Front forks stripped and rebuilt, 20w oil, extra pre-load on springs
Standard rear shock.
GSX1300R Rear sets with custom solid pegs and sliders.
13mm GN125 front Master Cylinder
Single Tokico Front 4 piston Caliper
XJR1200 Front Disc
Standard 2 piston rear Tokico Caliper
GSX250 Rear Disc
1982 TS125ER Engine Standard Porting (at this stage)
Boyesen Reeds
24mm OKO Carb with 100mm alloy Intake Trumpet
TF125 expanion chamber TS125 Exhaust and muffler
Chinese CDI Ignition box

My Question is as follows.
I have a #30 idle jet. and #100 main jet currently fitted to the carb but my bike is not running right. Does anyone have experience with PWK or similar carbs fitted to these engines that can give me any idea of jetting I will require. I have some rolling road time booked in the coming weeks but any input will be much appreciated.

Cheers, see you on the track

[TZ350]

.

Before the dyno session I would get rid of the trumpet and buy a range of main jets in every step from 90 to 160. A 100mm trumpet will make any descent 2T run like crap. NIKAU on Trademe is a good trader to try for the jets.

341394

[layton]

Cool! Can't wait to get out on the Nelson kart track

[jthespanner]

.

Before the dyno session I would get rid of the trumpet and buy a range of main jets in every step from 90 to 160. A 100mm trumpet will make any descent 2T run like crap. NIKAU on Trademe is a good trader to try for the jets.

341394

I originally had a short 40mm or so trumpet fitted to the carb. I was getting a lot of fuel scatter. I would end up with oil residue on the surrounding frame. It definitely runs a lot better with the longer trumpet. It starts a lot better and will actually rev. Previously it would barely do these.

I have every size jet from 80 to 150

[F5 Dave]

The right jet should sort that, lose the trumpet, TZ is right, you really just want a ring to smooth air from all directions but that will be minimal increase.

My RG50 had same inlet layout but with much more timing. It was pretty messy despite being tuned to a very high level with like over 400 dyno runs over many years.

The right jet for your bike could be anything. You mean 30 pilot jet I assume.

Your peak power will be about 6-7000rpm with that setup I'd guess. They are super lame from std but will haul a sheep up to the top paddock and not judge you for what happens next. :love:

Check out my build for Petes TF elsewhere . Heck he might even get it near a track one day if he'd just finish details off. Then we need a pipe moodded to get some revs so we can crank some real power.

[TZ350]

It definitely runs a lot better with the longer trumpet. I have every size jet from 80 to 150

Great, getting it to run well is the big battle and a good collection of jets is a great help.

If you want to start delving into two stroke tuning and porting theory, there is a lot of general 2S tuning tec info here:-

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page2000

And pages 500, 1000, 1500 are worth a visit too.

[jthespanner]

Ok so a few more main jets I ordered have finally arrived.

As of this afternoon #95 main jet fitted to carby. And I have reverted back to the 40mm trumpet I started with which is made from an intake boot out of an old GSXR1100 airbox I had lying around.

Fresh plug fitted BR7ES (one step hotter then standard) to help avoid fouling during tuning and I plan to run B8ES plugs (standard fitment) once tuning is sorted.

I have rewired the cheap Chinese ignition fitted to the bike. and tomorow I will wire an identical plug onto a spare TF125 CDI in case its the Chinese CDI that's causing my tuning woes.

Bring on the Dyno! I'll tke some photo's tomorrow. Any further suggestions would be greatly appreciated.

[F5 Dave]

Try a 9.

Erm std ignitions will hold you back to pedestrian revs,

[jthespanner]

Try a 9.
I thought NGK's numbers worked backwards. The smaller numbers were hotter?
https://www.ngk.com.au/technical_info/heat-range/



Erm std ignitions will hold you back to pedestrian revs,

I haven't fitted standard ignition. Just wired it up to quick change on the dyno for fault finding purposes if need be.

If I need to a programmable unit such as Ignitech is on the cards. Although I'll have to wire in a 12v battery total loss in order to run it..

[speedpro]

There's a couple of things you can try if you want to either blow a hole in the centre of the piston or nibble away the top edge.
1 - Use a hot plug
2 - Use poor fuel
3 - run it lean
4 - run it advanced
5 - all of the above.

I've had a lot of success with the above suggestions.

Put in a cold plug, fresh fuel, start with the biggest main jet you own, go easy on the timing, run rich oil mixture(40:1 with Motul 800)

Shit ignitions don't retard with revs so you either end up with too much advance at revs, it runs great at lower revs and blows a hole in the piston, OR, you back it off so it is good up top and it is weak at lower revs. What can feel good blasting up and down the street, or on the dyno, can wreck pistons on a track when thrashing.
Cold plug, good fuel, slightly rich, slightly retarded may knock the edge off but it should survive a thrashing. Extra fuel is useful to assist with cooling and keeping the motor perking once it gets real hot on about the 3rd lap.

Whatever you do, don't buy a 4-stroke

[TZ350]

If I need to a programmable unit such as Ignitech is on the cards. Although I'll have to wire in a 12v battery total loss in order to run it..

Team ESE uses light weight racing Lifan units and re wind them for 12Volts to run their Ignitec ignitions. They use a voltage rectifier/regulator and a capacitor. No battery required. For all the details follow the link below.


329021

How to make a decent light weight racing 12 Volt generator stator for the Suzuki GP/TF/TS RG50 from a Lifan after market magneto kit. We have spun these to 14,000 rpm plus on the dyno and they have proved reliable on the track.

[husaberg]

I thought NGK's numbers worked backwards. The smaller numbers were hotter?
https://www.ngk.com.au/technical_info/heat-range/
.

Hotter plugs glow practically incandescent in a highly tinned bike, useful for cold stating a diesel but not on a race two stroke.
As speedpro says hot plug = hole in piston.
You should not use anything below a 9.
With correct fueling it will run fine without fouling a NKG10 or higher.

[F5 Dave]

There's a couple of things you can try if you want to either blow a hole in the centre of the piston or nibble away the top edge.
1 - Use a hot plug
2 - Use poor fuel
3 - run it lean
4 - run it advanced
5 - all of the above.

I've had a lot of success with the above suggestions.

Put in a cold plug, fresh fuel, start with the biggest main jet you own, go easy on the timing, run rich oil mixture(40:1 with Motul 800)

Shit ignitions don't retard with revs so you either end up with too much advance at revs, it runs great at lower revs and blows a hole in the piston, OR, you back it off so it is good up top and it is weak at lower revs. What can feel good blasting up and down the street, or on the dyno, can wreck pistons on a track when thrashing.
Cold plug, good fuel, slightly rich, slightly retarded may knock the edge off but it should survive a thrashing. Extra fuel is useful to assist with cooling and keeping the motor perking once it gets real hot on about the 3rd lap.

Whatever you do, don't buy a 4-stroke

I run 40:1 in my dirty big slow revving 300. 30 for my 50 or 100.

But you wouldn't believe how awesome my 300 is.


Bwaaaarp. Fuk its amazing.

Sorry been out riding today. So much better than a poxy foul stroke.

[jthespanner]

I purchased an expansion chamber of a Malaysia special RGV150 (the air cooled one not the watercooled RGV150 people race).
https://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=85113&d=1202623108

I had to chop and weld a small bend into the down pipe as the exhaust port on the TS125 engine obviously comes out at a different angle to the RGV150 exhaust. No muffler fitted yet (hopefully this arrives Tuesday).

Took my bike for a quick blast around the block. HOLLY FECKBALLS what a difference!!! Clearly my original bodgy TF125/TS125 chamber and exhaust was the main restriction.

Cheers for all the info regarding hot plugs. I'll revert back to a colder one.

[jthespanner]

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-9/58616498_10214492375768602_5871988689051058176_n.j pg?_nc_cat=105&_nc_ht=scontent.fakl8-1.fna&oh=8f89f8be4972d84ab3b0e584739e8ce9&oe=5D2A6A7D

So I welded up some tubes chopped off an old bicycle trailer (of all things) to make up a dodgy looking exhaust using the standrd RGV150 muffler for now.

So results are in. My bike runs 100% better! :clap: The way it should have been in the first place.

I managed a few tuning runs around the streets outside my place of work. #95 main was way too lean. I jumped straight to a #110 knowing FXR's like a #118 (ish) on a 28mm OKO carb. Still a touch lean & confirmed this by looking at the sparking bolt.

Swapped in a #115. Reverted plug back to a B8ES (standard temperature plug for the TS125). Quickly re-checked the idle mixture adjustment. and added another 1/4 of a turn out to suit the shorter intake trumpet.

One last quick tuning run, and then pack up my tools and head out for afternoon tea with my family.

I plan to fit a B9ES plug (on advice from previous posts, cheers lads) and I will check the plug and probably swap in a #118 and maybe even a #120 main jet. I still need to replace the main gearbox seal behind the front sprocket as it has developed a leak due to the engine having previously sat dormant for a few years before I got off my arse to piece this bike together.

Also I need to lighten the flywheel as I have been informed from a couple of reliable sources that the crank will break at the flywheel when I rev the engine to higher than sheep shagging RPM.

I'm so relieved to finally be making some headway with the tune of my Bucket, as previously I felt like I was going round in circles with the tuning on this bike.

[jthespanner]

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-9/58377088_10214492376008608_4020528081310580736_n.j pg?_nc_cat=100&_nc_ht=scontent.fakl8-1.fna&oh=89a2410c962b99ca48b4ba7f5fff3c27&oe=5D3C63ED

[F5 Dave]

Well the muffler angle looks ridiculous, but the pipe doesn't care a jott so it maters not.

You'll find a lower seat devoid of foam will give a better feel. Actually looks quite good.

[F5 Dave]

Oh yeah, behind the sprocket, Bush that seals against the seal has an oring behind it so it doesn't leak down the inner of the Bush. Replace that too.

[speedpro]

That is not looking too bad.

BUT . . . . do not start with lean jets and go up. Put in the biggest you have and go down. Running lean will end in tears. It shouldn't run at full throttle with a BIG jet. If it still does then you need to find a bigger jet, and for goodness sake don't compare it to what a FXR uses.

[jthespanner]

So my TradeMe "Universal 2 Stroke" muffler arrived today.

https://i.ebayimg.com/images/g/3JQAAOSw2gxY0oiU/s-l300.jpg

Initial impressions, I was a little disappointed to realize how large the inlet diameter is. But it was so light compared to the standard RGV150 muffler. I never weighed it but it's easily a KG or more lighter.

So with weight saving also being quite desirable to me, I decided to remake the joining pipe and make the new muffler work. The outside diameter of my joining pipe fitted neatly inside the inlet of the new muffler. A little time with the pipe bender and mig weder at work and new light straight through muffler is fitted.

I cant get over how quiet a 2 stroke is compared to a 4 stroke. The noise restrictions we have at our local track are such that an FXR150 can't have any exhaust much louder than a standard muffler. A straight through muffler as I have just fitted would be booming on an FXR

I got some more tuning runs done after everyone had gone home from work. #115 main still appeared a little lean, and swapped in a #120. I'll try a #125 tomorrow evening. I just want to get the bike in the ball park tuning wise so as not to waste too much expensive Dyno time.

[husaberg]

So my TradeMe "Universal 2 Stroke" muffler arrived today.

https://i.ebayimg.com/images/g/3JQAAOSw2gxY0oiU/s-l300.jpg

Initial impressions, I was a little disappointed to realize how large the inlet diameter is. But it was so light compared to the standard RGV150 muffler. I never weighed it but it's easily a KG or more lighter.

So with weight saving also being quite desirable to me, I decided to remake the joining pipe and make the new muffler work. The outside diameter of my joining pipe fitted neatly inside the inlet of the new muffler. A little time with the pipe bender and mig weder at work and new light straight through muffler is fitted.

I cant get over how quiet a 2 stroke is compared to a 4 stroke. The noise restrictions we have at our local track are such that an FXR150 can't have any exhaust much louder than a standard muffler. A straight through muffler as I have just fitted would be booming on an FXR

I got some more tuning runs done after everyone had gone home from work. #115 main still appeared a little lean, and swapped in a #120. I'll try a #125 tomorrow evening. I just want to get the bike in the ball park tuning wise so as not to waste too much expensive Dyno time.

go to mico metals an buy some 75mm irrigation tube or go to a market gardener and ask for some, make your own and decent muffler shop will have fibregalss string packing

[speedpro]

Running it a bit lean will make it crisp on the throttle and even make good power on the dyno. However, the piston will get "crispy" on about lap 3. If you do insist on sneaking "up" on the jet sizes make sure you go past the ideal jet and see the power drop off a bit. That would be the jet I would run on the track for safety.

I wouldn't have bothered changing the muffler inlet pipe. All you need is the correct size restrictor/nozzle on the rear cone outlet and the pipe after that doesn't matter, as long as it stays larger.

[nodrog]

Isn't a TS a motocross / enduro engine?

[F5 Dave]

No. Clearly not. That would be a PE or an RM. Weren't you paying attention at Farm school?

[jthespanner]

Isn't a TS a motocross / enduro engine?

No. Clearly not. That would be a PE or an RM. Weren't you paying attention at Farm school?

MNZ rule 16.2 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Kart motor and transmission parts are not permitted.
There shall be no restriction on the make, type or design of carburettor, ignition, exhaust, piston, cam, valve springs or cooling system except for class eligibility.

The TS was road legal. My one was even road registered at some point as I have ownership papers from an old rego to help get it road legal again if I wanted. If a TF engine is legal under the rules then why is the TS not?

[husaberg]

MNZ rule 16.2 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Kart motor and transmission parts are not permitted.
There shall be no restriction on the make, type or design of carburettor, ignition, exhaust, piston, cam, valve springs or cooling system except for class eligibility.

The TS was road legal. My one was even road registered at some point as I have ownership papers from an old rego to help get it road legal again if I wanted. If a TF engine is legal under the rules then why is the TS not?

Dont worry about Nodrog hes yanking a chain.
Which is ironic considering the short leash Tina keeps him on.

[TZ350]

Isn't a TS a motocross / enduro engine?

No.... a TF or TS is a perfectly legal Bucket engine...

341616

This TF/TS 125 at 22rwhp in a NF4 chassis proved to be competitive and very reliable.

[nodrog]

Doesn't ER stand for Enduro Racer?

[husaberg]

Doesn't ER stand for Enduro Racer?

I see why you might be confused by that but in the case of the TS it was actually named after one of our best NZ biscuit tin physicists Ernest Rutherford who co-incidently also comes from Nelson.

[F5 Dave]

That's a common misconception Husa. It was really an attempt by the Japanese to capture the Farmer vernacular. But they misspelled it on the seat cover.

It should have been AR. Or ARR.

[nodrog]

A TS and a TF engine are different.

[husaberg]

That's a common misconception Husa. It was really an attempt by the Japanese to capture the Farmer vernacular. But they misspelled it on the seat cover.

It should have been AR. Or ARR.

Its a great theory, one that many people follow, But due to the strong anti communist feelings in the early 80's they couldn't go right out and say TS.AR
Because that was the emperor of Russia before 1917.
Not a lot of people still realise the Russians and japan are still legally at war so it never couldn't fly.
https://www.npr.org/2019/01/22/687319777/russia-and-japan-are-still-at-war-at-least-on-paper

[husaberg]

. Anyway who cares, its Buckets and combining the best parts from anything legal has been the way to go for ages.

Its also self policing according to the MNZ.
https://www.nzherald.co.nz/resizer/JCJgJKPEGhO-QtEcX6w8Ax6GrQ4=/360x384/filters:quality(70)/arc-anglerfish-syd-prod-nzme.s3.amazonaws.com/public/4KXWMTHJJNGBZI3NRNB6KW4WRI.jpg

[nodrog]

I feel a protest coming.

[husaberg]

I feel a protest coming.

You have been away a long time, i see you made a few changes to your assignment.

[F5 Dave]

Nah he's just being a cock smoker. Fuk me. TS competition engine.

Ball licker.

Probably licking Drew's balls atm. "Oh I'm such a troll. Teeheehee."

[nodrog]

Did I mention anywhere that it was me that would be protesting?

Competition engine or not, rules are rules and it's you precious cunts who have made them.

Or is it going to be another it's ok until they start winning scenario?

[husaberg]

Did I mention anywhere that it was me that would be protesting?

Competition engine or not, rules are rules and it's you precious cunts who have made them.

Or is it going to be another it's ok until they start winning scenario?

Jeeeez Gordon you were a lot more mellow pre-op

[F5 Dave]

Dude. It's a fucking road engine styled as a light traile. They are nowhere near competition based. Geez you only have to see how pedestrian the revs are or the power output is to see that. They were made to last 15 years between rebuilds running on whatever oil the local garage sold out of an old container on the forecourt.

And fuck sake they came out in the 70s. I think we've worked out where they sit in the pecking order.

[jthespanner]

Dude. It's a fucking road engine styled as a light traile. They are nowhere near competition based. Geez you only have to see how pedestrian the revs are or the power output is to see that. They were made to last 15 years between rebuilds running on whatever oil the local garage sold out of an old container on the forecourt.

And fuck sake they came out in the 70s. I think we've worked out where they sit in the pecking order.

Exactly! anyone with a dremmel and some knowledge could port a TF cylinder to be almost identical to a TM from 1970-1980. No one would disagree that fitting an entire TM engine into a 80's 250 frame is within the intent of the rules. But a TS125 is hardly a motocross rocket ship.

The reality is my engine still makes less horsepower than a stock FXR in "just add an oko carby and go race" form. This bucket has not been built doing anything different to what has been raced for years gone by. And I am sure plenty of other MNZ members race buckets with TF125 engines far hotter then I am running.

Ok rant over.

Can this thread please get back to the original point?

[jthespanner]

Got the new muffler and joining pipe all welded up the other day. Heaps lighter then either the original TF/TS125 exhaust I built for this bike, or the RGV150 muffler in earlier photo's.

Got in trouble doing another road tune. But currently running a #125 main jet and it's on the richer side. Time to get back in tough with the owner of the Dyno and get this thing properly sorted.

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-9/58722634_10214517440635208_3346823651608494080_o.j pg?_nc_cat=103&_nc_ht=scontent.fakl8-1.fna&oh=437477d080668ef0244acb8268f7d5cf&oe=5D36C91D

[TZ350]

.

A Honda RS125 NF4 expansion chamber works well and is relativly easy to fit.

341632

I have got them from this auction site, they ship internationally:- https://www.jauce.com/

341633 Honda RS125 NF4 pipe. The header bolts up hard to the cylinder and the main body is held to the header with springs.

The NF4 pipes are reasonably easy to fit. Mostly they just require a new header flange to bolt them to the cylinder.

341634 The later model NX4 pipe is lighter, more traditional type of racing pipe and has a much steeper header. Because of the header angle it is a bit harder to fit, but some cut and tuck will sort that.

Both pipes work well, even on a low tuned engine and work better as the tune is improved. I have successfully used these pipes on my builds from when I started at 18hp to a best ever 32 hp.

It is an interesting phenomenon that the same tuned length has suited both 18 and 32 hp but its easy to understand when you think about the exhaust heat and how it affects the tuned length.

The same tuned length for lower hp and lower rpm == higher hp and higher rpm.

[F5 Dave]

Only thing is that the headers on nf4 are enormous 3 bolt affairs

[TZ350]

Only thing is that the headers on nf4 are enormous 3 bolt affairs

Yes true, and we always cut them away and made new ones that adapted them to the cylinder. Did this without altering the tuned length.

Also the header pipe is enormous compared to the exhaust duct but it is a mistake to grind the exhaust duct out to match. The big step between duct and the larger pipe works Ok.

[nodrog]

Dude. It's a fucking road engine styled as a light traile. They are nowhere near competition based. Geez you only have to see how pedestrian the revs are or the power output is to see that. They were made to last 15 years between rebuilds running on whatever oil the local garage sold out of an old container on the forecourt.

And fuck sake they came out in the 70s. I think we've worked out where they sit in the pecking order.

I didn't make the retatded rules....

[speedpro]

It's like trying to have an intelligent discussion with a piece of would

[sidecar bob]

It's like trying to have an intelligent discussion with a piece of would

Quoting that in case you edit.:lol:

[eddie]

.

A Honda RS125 NF4 expansion chamber works well and is relativly easy to fit.

341632

I have got them from this auction site, they ship internationally:- https://www.jauce.com/

341633 Honda RS125 NF4 pipe. The header bolts up hard to the cylinder and the main body is held to the header with springs.

The NF4 pipes are reasonably easy to fit. Mostly they just require a new header flange to bolt them to the cylinder.

341634 The later model NX4 pipe is lighter, more traditional type of racing pipe and has a much steeper header. Because of the header angle it is a bit harder to fit, but some cut and tuck will sort that.

Both pipes work well, even on a low tuned engine and work better as the tune is improved. I have successfully used these pipes on my builds from when I started at 18hp to a best ever 32 hp.

It is an interesting phenomenon that the same tuned length has suited both 18 and 32 hp but its easy to understand when you think about the exhaust heat and how it affects the tuned length.

The same tuned length for lower hp and lower rpm == higher hp and higher rpm.

Hi can someone give me the specs to make the rs125 chamber thanks

[TZ350]

Hi can someone give me the specs to make the rs125 chamber thanks

341787 .................

[husaberg]

Hi can someone give me the specs to make the rs125 chamber thanks

there is a fair few more here as well.
but stick with the NF4
https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1131093900&highlight=rs125#post1131093900

[eddie]

Thanks thats been a big help , going by the parts book it has a short header pipe not included in the drawings do you have the spec for that also?
I see in the parts book it has an air box are they an improvement on an older race engine

[jthespanner]

We had a couple of months off racing over winter so I have had some time to get a few improvements ticked off my list.

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-9/69362323_10215332616814103_389602290215944192_n.jp g?_nc_cat=111&_nc_oc=AQnMLQmDpt5BCcGtPnHbOTcRHWtdolOqmdc_Y-14cmucKLNiYegoJYD_FZhFqXtHqis&_nc_ht=scontent.fakl8-1.fna&oh=fa07a7f0946748e577ee0a5b5b26ea68&oe=5DE10921

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-9/68662028_10215332617134111_9012107216949346304_n.j pg?_nc_cat=101&_nc_oc=AQkGibemtlezIjbTDfO7jq6pK-sDQnflsoSN17U222xYKIgG6IvI1CF7C9I-bVE5meY&_nc_ht=scontent.fakl8-1.fna&oh=1e6f39fad814a5e344a6e352dfef50a8&oe=5DD5F5AD

[jthespanner]

No.... a TF or TS is a perfectly legal Bucket engine...

341616

This TF/TS 125 at 22rwhp in a NF4 chassis proved to be competitive and very reliable.

Awesome looking bike, do you still race it?

[TZ350]

Awesome looking bike, do you still race it?

No, not my bike. It belongs to Rick 52

[Rick 52]

Great bike with lots of results, very reliable with good usable power, no longer a Bucket.

[jthespanner]

Right,

Well after building up my GSX250 frame with the TS125 engine I was a bit disappointed how much it weighed all up.

94 kg wet according to the scales at my local Kart track.

Time to redo this much better-er!!

So I found on TradeMe an old RG250 Gamma alloy frame and I decided to swap as much as I can off my GSXR Chassis and build my super bucket.

Parts purchased so far.

RG250 Frame
KLX300 swing arm
RM85 complete ignition setup including flywheel and CDI
KLX250 rear axle and chain adjusters
KLX250 rear brake setup

Parts I already have and will be adding to the mix
GSXR750 Ohlins rear shock
GSXR1100 rear suspension linkages
GSXR250 Front Forks
2 Sets of GSXR 250 Wheels (one with slicks fitted, others for wets)
2 XJR1200 front brake Discs (one for each wheel set)
GN250 Front Brake Master
TS125 Engine


My reasoning for using the KLX swing arm is because the TS125 engine mounts like most dirt bikes and the rear engine mount is the axle of the swing arm. I built vertical gussets on the GSXR frame and I won't be repeating that mistake 2nd time round.

The KLX had a larger diameter swing arm axle then my TS125/GSXR had so I turned some top hat spacers to adapt the KLX swingam into the RG250 frame. Width wise the KLX swing arm is perfect!!! it's like it was destined to go into an old Gamma frame. Gotta love how Suzuki (Kawasaki KLX250 = DRZ250) keep parts and dimmensions common across many models.

Moving onto rear wheel mounting.... The KLX has a much larger diameter axle than a GSXR250. I got the SKF bearing catalog out and tried to source a bearing to adapt GSXR wheels onto the KLX axle.... no joy the bearing I need doesn't exist/isn't common and I couldn't be bothered to strip down the rear wheel to get them machined out to make a bearing fit.

Plan B, I cut down the KLX axle and welded a short piece to each side cam shaped chain adjuster, RH side also catches the KLX caliper hanger, LH side only catches the swingarm and is welded to its own chain adjuster. I then turned both axle adapters on the lathe to true them and ran a 16.2mm drill bit through the centre to allow a standard GSXR250 rear axle to fit through the center. Boom GSXR rear wheel on standrd size bearings in a KLX swingarm.

I just need to center the rear wheel in the swingarm next. After some measuring I need to loose 16mm off the chain side somehow. I have purchased a FXR150 sprocket carrier as I'm hoping it will be a little narrower then a GSXR250 item. Hopefully this arrives soon and I can get the rear wheel fitted.

[jthespanner]

The GXR250 Frame, rear shock and Swingarm weighed 23.65 kg on the scales at work.

RG250 frame, KLX 300 swingarm, Ohlins rear shock 14.21 kg

9.44 kg down already!!!

I still have a few other parts I made out of steel last time I intend to redo out of alloy this time. Lets see how this all goes....

[jthespanner]

Hello all,

its been a long time since I have updated this thread.

It weighs 75kg wet!

Needless to say I'm totally stoked with how light it has ended up.

KX85 ignition setup and flywheel is all fitted and works well. The KX85 flywheel weighs around 400 grams and the TS125 flywheel it replaced weighs 900 grams (even after I lightened it on the lathe). Ignition timing is currently set at 22deg Before TDC and it runs well. Standard KX cdi appears to retard timing several degrees as the revs rise.

I also have just dug out a Trailtech Vapor dash I had left over from an oldd streetfighter project. So now I have a tacho and a shiftlight. dunno how much I need it or if I will even be able to see it while racing. But It ws just gathering dust in my shed previously so why not.

I still have a few tidying up things to get done (eg covers around ignition system on the frame) but the bike is pretty much ready to go.

See you on the track, Hopefully a mission to Tokoroa is on the cards sometime soon.
https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-0/p180x540/87261257_10216792747716463_9211559747214376960_o.j pg?_nc_cat=103&_nc_sid=110474&_nc_ohc=n35oWqrZplYAX-cSUti&_nc_ht=scontent.fakl8-1.fna&_nc_tp=6&oh=329fec941ab5a6e2f761744218fd22c0&oe=5EFBD062

[jthespanner]

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-0/p180x540/87373485_10216809979187239_5200840275991199744_o.j pg?_nc_cat=100&_nc_sid=1480c5&_nc_ohc=MdKTlppadfgAX8JWEPX&_nc_ht=scontent.fakl8-1.fna&_nc_tp=6&oh=cfd184cdbb590270e89fd30561d88721&oe=5EBD399B

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-9/87582004_10216817433093582_817796235975983104_n.jp g?_nc_cat=101&_nc_sid=110474&_nc_ohc=W-r2EocHqdIAX9yYdAb&_nc_ht=scontent.fakl8-1.fna&oh=c028afa0f0ed4e1411ff47f913cabfa4&oe=5EB6C6D7

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-9/86267335_10216817433693597_1290163001252380672_n.j pg?_nc_cat=109&_nc_sid=110474&_nc_ohc=uO9abayv-5kAX9btlU6&_nc_ht=scontent.fakl8-1.fna&oh=f929de0299a4849b3bc1ac2a095e067c&oe=5EBD2EF7

[TZ350]

.
75kg. that is very good.

[TZ350]

Standard KX cdi appears to retard timing several degrees as the revs rise.

The ignition might retard a bit but it could also be the capacitance of the timing lights trigger circuit delaying the strobe a bit as the rpm increases. The timing light maybe making it look like the ignition is retarding. Just something to keep in mind when strobing at elevated RPM. Anyway I like your bike and we have used KX80/85 ignitions ourselves and they worked great.

[koba]

Very cool!

There aren't many bikes out there in that weight range, well done!

Sent from my Nokia 6.1 using Tapatalk

[jthespanner]

Testing and Tuning runs all done.

I settled on a #125 Main jet, 1 clip raised needle to richen mid range a little, and #35 idle jet.

Wee list of things to sort before race day. I'm glad all these issues became apparent during shake down runs as any of them could have ruined a days racing.

New exhaust hanger (existing bodgy one broke due to vibation)

Loctite all screws and Nyloc nuts required EVERYWHERE as this engine buzzes at the dead right frequency to rattle everything loose astonishingly quickly!

Roll on Race Debut i'm getting excited now!!!!!!

https://scontent.fakl8-1.fna.fbcdn.net/v/t1.0-9/89027831_10216858012628045_5147255881754214400_n.j pg?_nc_cat=102&_nc_sid=1480c5&_nc_ohc=0rGyT94eIVkAX_RCbdY&_nc_ht=scontent.fakl8-1.fna&oh=943407c31132a1efd135478404819553&oe=5E978031

[jthespanner]

Ok so I need to apologize. I have unintentionally misled you all.

I re-checked the how much my bike weighs on the scales at the Kart track in between races this weekend just been.

90kg full of fuel was the result.

so 90kg - 6L of fuel at .75kg per litre = 85.5 kg with no fuel in the tank.

So why did the load cell I used read 10kg wrong? It's simple really, that load cell is designed to measure pressures in excess of 200 tons, so asking it to measure accurately less than 100kg is at the short end of its range and therefore not as accurate.

So don't worry lads its not as light as first thought.....

But I myself however am as light as you thought, and no I won't be gaining any weight any time soon.....

[koba]

Ahh, good spotting, that's still a good weight for the bike for sure.

Sent from my Nokia 6.1 using Tapatalk

[F5 Dave]

My RG50 was 59.5kg on kart track scales with no gas. Just saying