KR-1S.co.uk Forum

Put the motor back together today and she runs sound as a pound.When she is warm the revs will rise to 3000rpm and stay there.Eventually the revs drop but if you rev it again the revs stick.She is ok when cold and only happens when warm.An air leak?
IAN

yup sound like it...get some wd40 or brake/carb cleaner and spray it around your inlet rubbers..one at a time..if u have an air leak it will draw in the carb cleaner(very flammable),and the revs will rise then fall....give it time between each side and dont coat both cos you wont know what side is the problem...if not maybe float hight or pilot screw...but i reckon you do have an air leak...

definitly an air leak, had the same probelem and had to enter a race with it (gulp!) when i had std carbs. this is a risky buisness as the excess air been pulled into the mix can cause the bike to run dangerously lean if jetting is already on the lean side. almost every kr ive come across on oe rubbers suffers this problem. could be repaired or there are other, neater options as falconman demonstrated with his 35mm equipped bike. since fitting 35mm carbs the bike feels far smoother at a standstill(not ridden in anger yet and jetting needs optimising). the revs drop as quick as they rise and the sound is akin to a parralel tz250! you think the kr has massive induction roar with 28mm carbs? jesus, with bigger carbs they make yer ears bleed!! makes the highest tuned rgv's sound like a mt5!!! the kr has always been the best sounding proddy stroker in many peoples(inc ex rgv'er dean dicko) eyes so must be true. glad you got your top end woes sorted out finally mate, worth it in the end.

yup..air leaks on two smokes=kaboom...first check float heights,pilot settings,balancing...if its still got a problem you've got an air leak...get it sorted...

I've had "hanging @ 3k" before - balancing seems to make a good difference.

I suppose you could check it by setting both slides to close completly (no tickover) but I dont remember thinking of this at the time, maybe the carbs are not designed to close that much.

FoundTHIS to be a helpful thread setting up the carbs.

Cheers,
Charles

Thanks for replying.It did have an air leak and now its fixed!