my R is sick

[FreeStyle Digby]

Hi all this is my first post so go easy on me :)

right the problem is i have just done a top end rebuild on my 250R and now it will hardly run .I managed to get i started once but it sounded really chocked up
it has a Paul turner "race pipe" , 28mm pj carb with a 170 main jet (not sure about pilot) a ct tuned barrel (89 model) on 1.5 oversize with a pro x piston kit and a twinair filter

it has a good spark good compression (just been rebuilt) and the plug is wet so must be getting fuel in so im thinking it must be down to the jetting but im not to clued up on this side of things

before the re bore it was at 1mm over so could this increase to 1.5 mm put the jetting out ??

like i said i started once then after about 1 min it stalled and now will not restart

so if anyone has any ideas on what could be wrong i would love to hear em

many thanks F S D :) :)

[deathman53]

don't you mean a 38mm carb??? 170 is abit too rich, start with a 160 and go up. Do you still have the airbox lid on??

[FreeStyle Digby]

thanks for the reply
yeh its a 38mm
and it has a ally air box so no lid






cheers F S D

[deathman53]

go down to a 160 main, and work up as needed. Dumb question??? reeds new, how is the compression on the top end?? my bike fouled a plug(which it never does), when I pulled it out, it was jet black. I replaced the reeds and its card-board brown again.

[FreeStyle Digby]

the reeds are not new but look good (im not sure wot make they are)
it has loads of compression
i will try a 160 main will this make it better to start ?







cheers F S D

[peeping TOM]

try leaning the needle out ,, if its hard starting ,, but you could have just fouled the plug ....plugs just die a fast death sometimes ....even one's that haven't had a hard life ..

[ChvyCruzen]

You said the plug is wet, did you smell it or did you assume it is gas? It could be coolant too, not just gas. Double check that.

[lee37vernon]

did you do a leakdown test on it gav ?

[FreeStyle Digby]

Originally posted by lee37vernon
did you do a leakdown test on it gav ?

allright lee whot is a leekdown test ????







cheers F S D

[lee37vernon]

it's just to make sure you have no airleaks etc . should hold about 8psi for 10 minutes .
i made mine , old bike inner tube with valve , cut and bolted down under the exhaust flange . i have a 15psi turbo boost guage on the end of the valve , but with the inner valve removed .
on the inlet side i went to B&Q , used a plumbing blanking plug and another old inner tube valve with some araldite to seal it in . pump this side up with a bike pump tp 6psi , leave it . if its lost pressure you spray it down with some soapy water and look for the bubbles . this should tell you if your leaking anywhere , including into the coolant . you can at least rule out any airleaks for anything after a rebuild that way .

do a search on leakdown. you'll see some pics without much searching . this may not be related to any problems your having but it rules it out and its a good thing to do anyway, saves any costly mistakes .

[FreeStyle Digby]

She's Alive :D

well today i fitted a new plug and cap and a 160 jet and she went first kick :D :D :D :D :D
so i will get it run in tommoro and do a plug chop to make sure its not running lean and hopfully she will be all ready for a good ride at the weekend

thanks for all your advise chaps ;)




cheers F S D