Guys have just cleaned my carb ultrasonicly put it all back together. Kicked the bike over then it just revs and revs until it's about to burst!

2011 sherco 290.

I've checked manifolds for air leaks: all ok

Air fuel screw 1.5 turns out.

Makes no difference whether it's on the choke or not.

Any ideas before I kill my bike?

Thanks Boner.

check the carb top is on right

At a guess you haven't put the carb back together correctly, strip it back down and be meticulous when re assembling.

A few possibilities are - throttle valve binding, needle jammed or wrongly positioned, throttle cable not seated correctly either end

you could of just trapped your throttle cable, iv seen that happen twice now.

Slide in backwards? Missing parts for the air screw or idle?

The first thing I do after I put the carb back on the bike is open the throttle and let it snap back and listen for the slide hitting the tick over screw! ( with out the engine running) if you cant hear the slide knock something is not back right.

33 years back I had the same problem with my Ossa, I had taken the lights off including the switch which had the kill switch included, I tried a few times to pull the plug cap off but got electrocuted each time.

Check for the cable being pulled out of it`s seating at both ends, could be that simple.

The first thing I do after I put the carb back on the bike is open the throttle and let it snap back and listen for the slide hitting the tick over screw! ( with out the engine running) if you cant hear the slide knock something is not back right.

100%

Thanks for all the replies guys.

I had the rad off too to replace thermostat. When reassembling everything, I did pull the throttle cable up out of the way and slightly re-route it to tidy things up.

Could re-routing the throttle cable be enough to cause my bike's problem?

Cheers Boner

Most definitely, all it needs is not to be seated correctly at either end, make sure the outer cable sleeve are touching the stop at throttle and carbon. You may have inadvertently pulled the outer cable away from the stop when you have 're-routed the cable, it's an easy mistake to make.

Thank you.

I'll have a look later and report back.

Cheer Boner.

ALLWAYS perform a "plunk" test to hear the slide hit the stop after performing any maintenance and prior to starting motor.

Crank case seal...... Just had the same problems as you, went through everything you've losted above! 10min job and the part costs a fiver!! Easy fix mate!!

Throttle cable wasn't seted properly on the carb.

Fried the top end too :-(

Lesson learnt.