ESE's works engine tuner

**jasonu** · 19th February 2016, 18:49

Originally Posted by peewee

sounds to me like jan is still king and rsa is still most powerful 125 on the planet

A shame there is no class for it anymore.

**Yow Ling** · 19th February 2016, 20:36

Originally Posted by jasonu

A shame there is no class for it anymore.

They still run 125's with moto3 in BSB, the lease on a RSA125 might be a bit steep though

**Yow Ling** · 19th February 2016, 20:40

So the Ryger makes as much power as TZ350's GP125 they could have saved a bit of money doing this, I would not doubt Jans opinion his friends may be well connected in the 2t world.

**Bert** · 20th February 2016, 05:56

Rules....

Given the international presence on this page - im hoping someone maybe able to help.
(Sorry TZ for going left field - but it is two stroke related).

We are current writing some club rules for the inclusion of 250GP bikes (being twin cylinder two stokes GP not production) in our club series: given they are no longer part of our national manual of Motorsport - we are required to generate a set of supplementary rules for the 2016 season and permits.
Our fantastic national body can't seem to recover our documented national rules for consumption and reuse.
And I can't seem to find my older versions of NZ rules (was hunting it out for comparison around buckets) - in a box somewhere....
Would anyone internationally (or here in NZ) have access to technical rules for 250GP bikes and/or point me towards somewhere/someone whom might be able to help (rather quickly)...

Cheers
Brent

**d2t** · 21st February 2016, 13:27

Originally Posted by Bert

Rules....

http://www.usgpru.net
This is the premier organization for 125/250 racing in the USA. Go to the download section and there's a rulebook. More closely tied to club racing but follows the former Dorna-like professional experience. Hope that helps.

**sonic_v** · 21st February 2016, 14:42

Originally Posted by Bert

Rules....

Given the international presence on this page - im hoping someone maybe able to help.
(Sorry TZ for going left field - but it is two stroke related).

We are current writing some club rules for the inclusion of 250GP bikes (being twin cylinder two stokes GP not production) in our club series: given they are no longer part of our national manual of Motorsport - we are required to generate a set of supplementary rules for the 2016 season and permits.
Our fantastic national body can't seem to recover our documented national rules for consumption and reuse.
And I can't seem to find my older versions of NZ rules (was hunting it out for comparison around buckets) - in a box somewhere....
Would anyone internationally (or here in NZ) have access to technical rules for 250GP bikes and/or point me towards somewhere/someone whom might be able to help (rather quickly)...

Cheers
Brent

http://www.spelregels.eu/rules/motor...ING_GP_Eng.pdf

FIM technical rules for 2009 season.

**Bert** · 21st February 2016, 17:00

Magics thanks Gents - a little more full on than I was expecting - but the key elements are there to hack into our wider rule set..

**marsheng** · 21st February 2016, 19:52

Hi Chaps, I'm at a loose end here. Both KR150s exhibit the same wear patterns after an hour or less of racing.

Bike 1 new pistons (x2) in the original coated bore with a loose fit but within spec
Bike 2 new piston in a new cast iron bore with new tight (correct 0.05mm) fit.

Bottom of pistons shows no signs of overheating underneath the piston crown.

Bike 2 also had a really serious deep score mark where the rings ends meet.

Bike 1 uses TTS and bike 2 uses Spectro Platinum XS. Both bikes are using the standard auto lube system.

Open to suggestions.

**mr bucketracer** · 21st February 2016, 20:02

Originally Posted by marsheng

Hi Chaps, I'm at a loose end here. Both KR150s exhibit the same wear patterns after an hour or less of racing.

Bike 1 new pistons (x2) in the original coated bore with a loose fit but within spec
Bike 2 new piston in a new cast iron bore with new tight (correct 0.05mm) fit.

Bottom of pistons shows no signs of overheating underneath the piston crown.

Bike 2 also had a really serious deep score mark where the rings ends meet.

Bike 1 uses TTS and bike 2 uses Spectro Platinum XS. Both bikes are using the standard auto lube system.

Open to suggestions.

my 250 twin did that to my pistons more one of the 2 pistons , i got sick of it and sold it , turned out it was leaking seals and sucking in air making it run lean ?

**TZ350** · 21st February 2016, 20:04

Or water .... water breaks down the oil film.

**speedpro** · 21st February 2016, 20:06

Ring gap a bit tight causing score of bore and if it runs good with throttle then maybe the pilot jet is small, or an air leak, both making it lean on overrun and the piston trying to nip up causing the scuffs on the pistons. Do not re use the pistons once this happens. A careful measure will show they have changed shape, permanently

**Flettner** · 21st February 2016, 20:13

Piston is not uncovering the eye ports at TDC are they?

**marsheng** · 21st February 2016, 20:48

Originally Posted by speedpro

Ring gap a bit tight causing score of bore and if it runs good with throttle then maybe the pilot jet is small, or an air leak, both making it lean on overrun and the piston trying to nip up causing the scuffs on the pistons.

New bearings, conrod and crank seals in both motors.

The original bike had 40K on the clock and the piston and bore looked ok. As these are still running the standard ignition, ie no retard at max RPM, (I think) could it be that this is causing the overheating issue when used as a race bike and max RPM most of the time?

PS this is at Ruapuna full track so they are being given a good workout. .

Thanks Wallace.

**JanBros** · 21st February 2016, 22:57

Originally Posted by marsheng

don't know if the original KR150 piston has holes in it's skirt, but a KR1 piston has them to lube the bridge between main and aux exhaust ports (which gets realy hot). I'd drill some holes in the skirt :

and if you use a piston with the ring pin in the C-port, you could also drill holes in the skirt between B and C ports.