wr426 high idle

just bought this bike it has $765 of receipts just done to it to correct the high idle in which the shop didnt succeed, when i rev it sometimes it takes 5-10sec before it will return to idle and sometimes doesnt return at all. i am uncertain on exactly what they did but can anyone suggest anything it could be? the carby was cleaned and all adjusted, when i also give it full revs it crackles a bit and backfires on de-excel. any help would be great cheers.

Edited by jonesy383

Could have an air leak in the intake, is your exhaust bolted up okay? What is the timing like can you check this. Check the air filter to ensure it is clean and re oiled.

yeh exhaust is bolted up ok, theres a few lines running from the carby into the air box, and theres a big black hose with a little filter on it inside the air box as well not sure if its all supposed to be there?

What about timing?

Check if the little o ring that seals around fuel screw is good, below that it needs a small washer. Its getting air from somewhere it shouldnt, an easy way to find it is with start spray, and spray gentley around the carb with the engine running, and listen if the rpm raises

Check the carb boot from the carb to the cylinder for cracks. For sure an air leak.

ok thanks guys i found a hairline crack in the rubber boot you are talking about jc. also it makes a crackling noise when i rev it and backfires a bit could this be the cause of it being tuned while it is leaking air through the rubber boot? will a new tune fix this after i repair the boot?

yeh i did read that but i assumed after spending $700 at a shop this would have been adjusted lol, i might have a play around with it cheers

First mechanic's rule ..... always assume any work that was done was done wrong.

ok so heres my dilemma, when i screw the fuel screw all the way in the bike still runs ok. i need to unwind it all the way out for it to run sweet again (so much that i lost the fuel screw) so do i need to change my jets? i dont know much about carbys :/

You've got to fix that air leak first. You'll be chasing your tail, trying to no avail, if you try to tune the bike before fixing that air leak. After that, check out the stickies at the top of this forum. Lots of good info in there, that's what they are there for! After that, we'll help all we can to get that bike running perfect!!


i think the high idle was the cause of the pilot jet being too small. i went to a 45, 1-1/2 turns out and the bike is running sweet now :cry: there was no air leak, thanks eveyone for your help

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