ESE's works engine tuner

[Skunk]

Thanks for the tip. I looked the engine up. Bored+Stroked = 130+cc and running on methanol = 55+Hp at the crank.

From what I can make out the standard 125 version on pump fuel is in the low/mid 30's for Hp.

Very encouraging though, bSo it might be possible to make a F4 GP125 with a mid 20's rwhp setup for long tracks, too late for the Taupo TRRS this Xmas but maybe for next time.

Next year looks interesting already, the promised land beckons.

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Kaitoke is ready for you to do testing!
I'd be interested in seeing how you go improving the airflow though the 24mm. I'm not into the engine building as I like building the bike itself.

[F5 Dave]

. . .
Plus some other ideas like bronze clutch plates and a gear box oil cooler so I can really cane it coming out of the corners.
. . .

Sorry? What is wrong with the clutch? Suzuki plates take some real beating as demonstrated by my long suffering RG50 clutch. No bike gets more of a clutch hammering to be sure. While adjusting the lever I did get some suspicion of slip at Kiatoke up the hill last week. But I had the lever with minimal adjustment at the time so maybe not. Oh well I had some new plates in the spares for some reason (I run TS125 plates). measured difference after heck maybe 6-7 year of extreme abuse; 0.1mm difference. Word.

[jasonu]

That’s very interesting, could the difference between the RS pipe stopping dead on your bike and it reving on, on an RS125 be the retarding ignition that the RS uses? do you have any dyno graphs or dimensions of the pipes you could post?

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I'll do my best. However, it was built 10 years ago, I now live in the States and the graphs etc are at my mates place in Titirangi. But I will try.[/QUOTE]

Here are the dyno graphs for my RG 400 barrel KE125 bottom end bucket. I had to go over them with a pen because my emailed copies are very faded and hard to see. However, they are accurate.
This motor was built 11 years ago. I got 2nd in the Ohakea GP behind Morley Sherriffs (I still don't know how he kept that pile of shit going...) and in front of Jimmy Steadman. It ran at a Manfield national where F5Dave got a ride and at a Taupo (old track) meet in F3 where it was good and fast as we had corrected a high compression cockup. That is when development stopped and we are sure (read we know) it will give more.

[jasonu]

Some pix of the 2 pipes. The RS pipe is a 1991 with a hand made header. The last pic has the TZ500 pipe fitted. Never mind the fat bastard in the background, it is the only pic I have that shows that pipe.

[Buckets4Me]

Sorry? What is wrong with the clutch? Suzuki plates take some real beating as demonstrated by my long suffering RG50 clutch. No bike gets more of a clutch hammering to be sure. While adjusting the lever I did get some suspicion of slip at Kiatoke up the hill last week. But I had the lever with minimal adjustment at the time so maybe not. Oh well I had some new plates in the spares for some reason (I run TS125 plates). measured difference after heck maybe 6-7 year of extreme abuse; 0.1mm difference. Word.

I think you will find that TZ350 also abuses the clutch much like you do
just he has a slightly bigger bore stroke to help out with munching those fiber things apart ( I saw a clutch basket fly apart on his tz350 and he still beat everyone off the start line)
I do believe that he hasn't put more than one NEW clutch in his bucket. And it's still good (at the moment)

[speedpro]

I do believe that F5s RG50 clutch has never been fully engaged with the engine running and in gear, ever! Since he's owned it anyway.

[Buckets4Me]

I do believe that F5s RG50 clutch has never been fully engaged with the engine running and in gear, ever! Since he's owned it anyway.

that i could belive

[TZ350]

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My bikes engine is dragging twice the weight of F5's with maybe twice the HP, the clutch does suffer.

the crankcase's run about 100 degrees C or a little more even though I have improved the thermal barrier between them and the barrel

I have not burnt the clutch friction material right off the clutch plates yet

but the inner steels turn blue the oil smells burnt and the friction plates become cooked hard during a hectic days racing

if you think about it there are a few benifits to running with cooler oil..............

.

[TZ350]

Some pix of the 2 pipes. The RS pipe is a 1991 with a hand made header. The last pic has the TZ500 pipe fitted. Never mind the fat bastard in the background, it is the only pic I have that shows that pipe.

Thanks for the pics and dyno graphs, interesting little peak on the TZ graph, nice wide power band too, I wasn't expecting that from a mid 20's rwhp 100.

Do you recall any of the engine details like the inlet closing point?

.

[jasonu]

Thanks for the pics and dyno graphs, interesting little peak on the TZ graph, nice wide power band too, I wasn't expecting that from a mid 20's rwhp 100.

Do you recall any of the engine details like the inlet closing point?

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The TZ500 pipe graph was the last run of the night and it never went back on the dyno so we are positive we can tune the 'peak' part of the curve to something better.
I don't recall any port timing numbers but when I built it I used A. Graham Bells 2 Stroke Tuners Guide as a starting point and went from there. The actual number will be close to what you find in the book and I do remember it is a fairly mild number. The good thing with the disk valve motor is if you do cock it up, you can simply bolt on another disk and try again. I know people say that book is old hat but it is still relavent to a lot of buckets as they are generally old hat motors.

[B.Crump]

a little off what you guys are talking about could somone point me to a thred that will tell me how much better a water cooled head is and what pump to use etc (tf125) cheers

[Buckets4Me]

a little off what you guys are talking about could somone point me to a thred that will tell me how much better a water cooled head is and what pump to use etc (tf125) cheers

this thread would be a good start

20hp from a watercooled 100
20hp from an aircooled 125 with 24mm carb

you think that the advantages of watercooling are there ???
or keap it simple stupid (KISS) ??

[speedpro]

definite advantage

[SS90]

Unquestionable advantage.

The most obvious is that the cylinder compresson ratios you are able to run are increased dramatically (reducing the likelyhood of detonation), as well as a more cosistant power throughout the entire race (i.e less likely to "power fade")

and perhaps the most important is, in a high spec engine a more consistant temperature reduces the likelyhood of siezures as well.....

So, I would say A water cooled two stroke head brings increased reliabilty and power.

Could someone please over complicate that for us?

[speedpro]

Been there, done that, gonna do it again. It makes a huge difference. On a TS you really need to limit the compression to about 14.7:1. If you water cool the head you should be able to go to 15.2:1. Perks things up nicely but it gets touchy on jetting and timing at that compression. You will need 100 octane and something like a YZ80 ignition. With the standard ignition you will end up with a hole in the piston if you can get it to run. Again - been there done that.