I have a proplem with my warrior I am pulling my hair out with. The bike will not start cranking it over with electric starter. It will start when you pull it with another bike poping the clutch. After it starts it runs strong but will not idle below about 1000 rpm. You have to push some throtle to keep it running. I dont see any vacuum leaks and the carb has been replaced along with the fuel and plug. Does anyone have an idea what the proplem might be any help would be greatly appreicated.

 

maby your idle screw isnt right, futs with that so it idles more

 

Thank for reply, but it needs to have throttle pushed more than idle screw can give it to stay running.

 

Sounds like the carb boot is ripped. You are sucking air into the engine between the carb and the cylinder. That black boot that connects the 2 probably has a rip or tear in it or it's loose somehow.

 

I'm with ridinwarrior.
This is a typical problem on all the Yamaha 4 stroke quads except the Grizzly660 and Raptor.

If that's OK, ccheck the float bowl vent tube coming from the carb. It may have some dirt or mud in it restricting the air path except for when you put a greater vaccum on it by giving it more throttle.

 

One possible problem could be that your idle to 1/3 throttle is a bit lean. If your exhaust pipe makes any abnormal sputters or pops when decellerating without the brake it may be the cause. Lean conditions make the quad a pain in the **** to start.