Hi all, i have just treated myselfe to an 06 scorpa sy 250, The problem is that i need more power from it, i am used to riding a TYZ that was breathed on by Nigel Birrket and that must be 50% more powerful in every way than the scorpa, dont get me wrong if you have poor throttle control the scorpa is the bike for you because it just bogs through the section, i am thinking of swapping the barrel and piston from the TYZ, but i dont want to do this if there is an easier option "jetting,timing etc", So if anyone out there can help i would be very grateful.

Alan

Edited November 12, 200619 yr by ScrumpyJack

Scumpy

you need to change your bike from the "UK" spec to the "Racing" spec as sold in most other markets.

To do this you will need to

- Lighten the flywheel

- Advance the ignition timing (HERE)

- reduce the main jet to a 136 (ish). The standard 145 is pretty conservative and runs a bit rich up top, not letting the bike rev cleanly. (I have run as low as 123 with absolutely no problems)

- and if you can be bothered, go the thinner base gasket.

Then it will HONK!

Edited November 12, 200619 yr by arnoux

Thanks arnoux, that will be my mision this week..! i still cant believe how tame the UK spec bike is,, does anyone really like it like that??

Alan

Did you do the mods ??

My old O2 bike was fine in standard trim, a mate had a 'racing' version...very pokey indeed, too much for me!.

It felt like a 280 Gas Gas..fine if you like that sort of thing

Thanks arnoux, that will be my mision this week..! i still cant believe how tame the UK spec bike is,, does anyone really like it like that??

I rode the UK and the Jap spec bikes back to back and really coldn't get on with the more powerful version.

Perhaps if I rode in dry rocky trials with big steps the more powerful version wold be better, but for the sort of wet muddy off cambered sections which I encounter, the tame version is brilliant.

In fact, you will laugh at me here, I have even fitted the slow action throttle.... and that helps even more!

But lets just clarify something.... I'm rubbish.

Click to see me being rubbish :-)

So it's just whatever suits you best.

Edited November 26, 200619 yr by scorpa3

Yes i have started to make changes,, i spoke to Birkett and he told me to try advancing the timing plate by 3mm, this is about half as much as the scorpa racing, it was instantly better and very simple to do, i still run with the heavy flywheel but i will be trying the lighter one from my TYZ at some point. I have also got a 135 main jet that i will fit next time i have the carb off, what i will do soon is go for a practice and try the timing in other positions.

Another problem i seem to have is the rear shock gets more bouncy the longer i ride it..! has anyone else had this problem?? i think i will get it rebuilt to higher tolerences,, apart from that it is a great bike and i love being able to play about with it to get it how i like it,,, some times you buy a new bike and just have to live with it as is......but i loved my TYZ and the scorpa is getting there!!

Scrumpy

scrumpy are you a centre champion?

i cant belive the scorpa is not powerfull enough for you???

they are really soft of the bottom i will agree but when you wind them up they rev out really well

what oil/mixture you running??

Yes i have started to make changes,, i spoke to Birkett and he told me to try advancing the timing plate by 3mm, this is about half as much as the scorpa racing, it was instantly better and very simple to do, i still run with the heavy flywheel but i will be trying the lighter one from my TYZ at some point. I have also got a 135 main jet that i will fit next time i have the carb off, what i will do soon is go for a practice and try the timing in other positions.

Another problem i seem to have is the rear shock gets more bouncy the longer i ride it..! has anyone else had this problem?? i think i will get it rebuilt to higher tolerences,, apart from that it is a great bike and i love being able to play about with it to get it how i like it,,, some times you buy a new bike and just have to live with it as is......but i loved my TYZ and the scorpa is getting there!!

Scrumpy

Ive fitted a lighter flywheel (about half of it off) and advanced the timing plate and its about the same as my mates 07 250 gasser with a keihin carb on. but i like it because it still grips extremely well. best bike ive ever had.

The other week I put on a larger clutch m/cylinder and its made the clutch a lot lighter.

You will notice a big difference with the lighter flywheel and is well worth doing IMO

good luck with it.

Not powerful enough is not the way i would put it... it just doesnt deliver the power as i would like it to, example: i believe you find the grip with good throttle control, and that is what i am used to,, suddenly having a bike that i feel has to catch up to what i am doing with the throttle is playing havoc with my timing (how i shift my body weight as i turn the throttle)... and no i am not centre champion...although i have been kicking ass on a twinshock fantic for a number of years!! "if anyone wants a pic of my trick fantic just ask" and my TYZ is still a great all rounder.. its nice to sit between sections in the bigger trials and nationals.

Scrumpy