Guys have just stripped my carb after my 2011 290 started and revved out until I eventually killed it with the switch.

I've cleaned everything thoroughly and blown it through.

Put the carb back together, fresh (new 50:1) fuel, kicked and kicked and nothing, not even a fart... The spark is good, but the plug comes out dry after kicking.

The reving out was caused by a badly routed / incorrectly seated throttle cable. The rest of it I can't figure out?!?

Cheers Boner

First things first, when you snap the throttle closed can you hear the slide bottom out?

A rev out shouldn't break the bike unless it's going for some time. It is possible to overheat the cylinder and mini-seize the piston smearing the aluminum and causing the rings to stick in their grooves but that is probably not what's going on in your case. Certainly not at 50:1. You can check your compression if you think that might have happened.

Not trying to be a jerk but do you have fuel flow? I say that from experience, kicking only to find I left the tap off. You could have sucked in a reed. That would make it tough to start as there is no intake port to speak of and the crankcase charge would be insufficient at low starting RPM. Is your kill switch sticking? Common on a Beta. Actually I think it's mandatory on a Beta.

The fact you could kill it with the switch is a good sign as it means the cylinder didn't get hot enough to go into pre-ignition.

Did you try using the choke?

Could you have reassembled the carb wrong? I have on occasion. I've also had dealers do it as well.

I think you may be in for another disassemble and careful reassembly of the carb just to be sure. I'm sure it's something simple. It usually is for a drastic failure mode.

Edited January 27, 201511 yr by dan williams

You did not mention which carb is on your bike. If it is a dell'orto you may have put the floats in upside down.Don't worry you are not the first.

Thanks chaps.

I'm sure that the slide is snapping ok.

Yes it's a Dellorto.

I'm just wandering if I've put the floats in upside down!

I'll have a look tmorrow!

Cheers matt

Edited January 27, 201511 yr by boner

Flywheel key

Is it worth pulling the head to double check for pre-ignition?

Is there any way of checking the flywheel key without pulling the flywheel? Presumably if the flywheel is turning that's good isn't it?

Cheers - Boner.

I thpught it was the kehin carb on the 290 ?

Have you tried a new plug ?

Drop some fuel down the plug hole and then kick. That often cures these sort of problems and clears bits out when the bike starts. If it doesnt start this way ......youve got problems. Good luck

I stripped the bike this afternoon. Had a hunch that it might be the top end pulled the cylinder - and hey presto rather sad looking piston and very worn rings.
I'm guessing therefore, there wasn't enough compression to draw fuel through the carb.

Off to the Sherco shop to see if the barrel can be saved :-(

Cheers - Boner.

Bits back from sherco. Resleeved, and all new top end.

Started first kick.