Any Ideas

[thescoot]

Just wondering if anyone knows much about sorting the sy250.Just bought the bike and love it but i am used to a 315cota and having a bit trouble adjusting to the extreemly soft power delivery.I would love to get the motor somewere between the two.I know to adjust the ignition timing but do i advance or retard it? to get a bit more get up and go.I have access to machining and would like to lighten the flywheel to obtain more responce.I read somewere to take it down to 2800gms.Does anyone know where to machine from ie outer face or external diameter?Any help will be greatly appreciated.While im on,the bottom end is somewhat noisy and while several owners i have spoken to say its nothing to worry about i like things to be perfect.There is a bit of play on the mains and i would rather sort it now than wait for it to go pop.Any opinions?

[motojojo]

I would check your timing and bet that its retarded right now, it needs to be set back to stock or advanced. I would check your jetting also. Good luck.

[arnoux]

There is a photo essay on The Hell Team / Scorpa Australia website about SY250R timing.

Scorpa Timing - The Hell Team.

The bikes delivered in the 03 - 06 years in Britain had a more retarded timing than the bikes delivered to Australia. They also had a heavier flywheel. Not sure about the current models settings in the UK.

The timing mark on the stator plate is stock Yamaha timing or British timing. It can be advanced from this mark for a snappier response.

What year is your bike?

If it is more than a couple of years old it could be the middle box muffler and final muffler gummed up - this will really choke a two strokes power.

When were the rings last done?

There is heaps of power on tap with a Scorpa motor if you know how to release it. But you do need to start with a clean, well built system first. Give us some more information if you can. And we can better advise you on a course of action.

Arnoux

[lee harris]

I believe that Scorpas sold to the uk had a "heavy" flywheel when compared to bokes from the continent! I know that some were importing bikes to the uk and the importer was warning of low grip! maybe call Birkett and ask?

Lee

[thescoot]

There is a photo essay on The Hell Team / Scorpa Australia website about SY250R timing.

Scorpa Timing - The Hell Team.

The bikes delivered in the 03 - 06 years in Britain had a more retarded timing than the bikes delivered to Australia. They also had a heavier flywheel. Not sure about the current models settings in the UK.

The timing mark on the stator plate is stock Yamaha timing or British timing. It can be advanced from this mark for a snappier response.

What year is your bike?

If it is more than a couple of years old it could be the middle box muffler and final muffler gummed up - this will really choke a two strokes power.

When were the rings last done?

There is heaps of power on tap with a Scorpa motor if you know how to release it. But you do need to start with a clean, well built system first. Give us some more information if you can. And we can better advise you on a course of action.

Arnoux

Thanks for the reply Arnoux.The bikes a 2002 model which although getting on a bit is in great condition.Iv had the motor to bits and replaced the main bearings(it still knocks though)so while the fly was off iv checked the timing which is set at what i assume is the standard yamaha marks.I have been told to turn the stator fully back in an anti clockwise direction but this seems a touch excessive to me.what would this do? Advance/retard/or destroy?While it was in bits,i also smoothed out the trasfer ports to help the mixture flow a bit better but am told there is another porting mod which is often done.Do you know what this mod is?Also machined 200 gms from the fly which has made a huge differance to the responce.Chacked and cleaned the middle and rear boxes which were in fact quite clear.I do however think it needs a piston kit fitting(when money allows)Any advice you could offer will be greatly appreciated. Mark