ESE's works engine tuner

[all4A50s]

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Check the size of the rotary valve ports

Attachment 230305

My GP will have an inlet port that looks like this soon .......

And I have an idea how I could make a variable port where the closing point can be changed, much like a blade power valve.

I didn't know an engine could just consist of carbs and exhaust. Do the carb restrictions still apply?

[TZ350]

Do the carb restrictions still apply?

125's are still restricted to 24, some doubt about the legality of oversized carbes sleeved back to 24.

But I have other carbs, pumper and plug/slide that meet the spec by any definition, that I can run if needs be. One flows more than the unit I am using now.

[Henk]

I didn't know an engine could just consist of carbs and exhaust. Do the carb restrictions still apply?

No carb or cooling restrictions on 100s

[TZ350]

I got a 29hp engine on triple-r-superbike dyno, the clutch was slipping bad and it was sucking in gearbox oil so i am sure there is a bit more power, i was running a 33mm vmx carb but am going to try a 28mm pwk carb, i have fixed the clutch with a new kit and added stronger springs, also fixed the oil issue with new seals and more GOO around the rotary disk cover. Its running a cr125 ignition which i want to replace with a zeetronic so i can make use of the powervalve and sort a good tune out.

I had a look at the www.FXR150.co.nz site, and see there are one or two more very fast 2-strokers in the pipe line down south and a bunch of very interesting FXR's.

[F5 Dave]

Cri..st I was feeling cocky untill I saw your bike ...........

Of more concern is Bren is a pretty shit hot rider into the package. If Nigel can get himself fit & willing to ride 100% & Bren can get his sorry arse up to Taupo it would be a race worth watching.

[F5 Dave]

I got a 29hp engine on triple-r-superbike dyno, the clutch was slipping bad and it was sucking in gearbox oil so i am sure there is a bit more power, i was running a 33mm vmx carb but am going to try a 28mm pwk carb,. . .

Betterer & betterer! I'd be searching around for other carbs to try, space is an issue on the old Joe, but with some case shaving & moving the inlet a bit it'd be fun to try a 34 or 35mm. Wonder if some of those short bodied MX125 carbs may fit in & work well. PWK35 is quite a size up from the 28. FCR conversion are too downdraft. . .hmm.

[Bren_chch]

cheers Dave - ahhhh so i should be going biggerer!! Mike has as cr125 carb laying in some dust, i think its 35mm or even bigger?? , maybe i can borrow that for testing! actually i got a rg400 carb too, what you rekon???

oh kinda stealing this therad a little. sorry ESE

yippeeee

[richban]

cheers Dave - ahhhh so i should be going biggerer!! Mike has as cr125 carb laying in some dust, i think its 35mm or even bigger?? , maybe i can borrow that for testing! actually i got a rg400 carb too, what you rekon???

oh kinda stealing this therad a little. sorry ESE

yippeeee

Been trying to find the flow figures for the 32pwk on the FXR. I think it was close to 124 cfm 32hp ish. So a PWK33 might be a good option to try. The difference between the 30 and 32 on the dyno was 1.4 hp at the top nothing in the middle. The head will flow 32.5hp. Note sure if that helps but them pwks flow well. Old TM 28 Mikuni 110cfm max potential 27.5hp no good to you.

[Buckets4Me]

oh kinda stealing this therad a little. sorry ESE

yippeeee

Steel the thread all you like
as long as there are pictures and stories to go with it
the tread is all about making a fast 2 smoker for the TRRS

and sharing idears around

[F5 Dave]

I certainly reckon its worth trying, assuming your inlet is ok for it.

[bucketracer]

Flow tested some carbs today. Thomas made up a manometer, which proved to be very effective at measuring flow through the carburetors.

Thomas made the manometer from some clear tube an old tape measure and some din rail and filled it with anti freeze and it worked a treat. He's a clever fellow is Thomas.

There are a number of posts here about Thomas and TeeZee's method of measuring which carbs and modifications flowed better.

[bucketracer]

Putting TeeZee’s 1978 Suzuki GP125 29.9 rwhp (33hp at the crank) into perspective.



Suzuki RT63 1963
Engine type: Air-cooled 123.70 cc twin cylinder rotary valve 2-stroke. 25.5 ps/ 12.000 rpm.
Bore x stroke: 43.0 x 42.6 mm
Carburetor type: M24
Compression ratio: 8.8:1
Top speed: 184 kph
Clutch type: Dry multiple plates
Transmission: 8 gears
Tyres: 2.50-18 / 2.50-18
Brake type (front): 2 drums, 1 cam
Brake type (rear): 1 drum, 1 cam



Honda MT125R Hondas 1978 over the counter 125 Racer. The tuned versions were 23-25 rwhp (26-28hp at the crank)



29.9 rwhp from a tuned learner bike dating from the late 70’s is not all that bad.

And better than the Honda factory was doing with their own 125 aircooled racer from the same period or the Suzuki factory GP aircooled racer from the period of factory Grand Pix competition in the 60's.

[jasonu]

the bike.... And engine finished

i like it!!!

[kel]

I got a 29hp engine on triple-r-superbike dyno,
I would actually like to send all my spec/info to wobbly and see if he has any ideas on what else i could do to make it better.

Holly crap Assuming your motor is peaking at 13000rpm that gives you a BMEP of approximately 11 bar, that is some phenomenal backyard engineering that you should be extremely proud of

[Bren_chch]

yow ling had a carb or two laying around so i borrowed them, will tell him later!

I thnk i have lucked on something again, not sure what but i need to go back and see what i changed when i rebuilt the motor, or maybe its just the clutch is actually working 100%, engine seems a lot stronger, but i did widen the inlet and and added a bit more advance on the timing, engine seems to pull harder... that is when i dont bog it down off the start.

uploading a little driveway test to youtube now, will add to thread after dinner.