Hey guys I recently purchased a 99 400EX and I'm having a bit of a problem with the choke, the butterfly is closing but the rpm's aren't going up, any idea of what could be wrong?

Thanks for any suggestions/help.

Thanks,

Tom

 

A lot of folks remove the butterfly for better airflow. It is a pumper carb, so I just push the throtle a couple times before a cold start, and that injects raw fuel and primes it so I never even need to use the choke.

 

That's intersting but mine still has the butterfly and for the most part I doubt I will be using the choke often(like you) but I do wish I could fix it and get it to idle a bit higher, any idea of what the problem may be?

 

How far closed is your butterfly going? Do you have a spare carb. to compare it to?

 

It closes all the way (as far as I could see), no spare carb here.

 

You want it to idle higher? When? When it's cold? After it's warmed up?
If you want it to idle higher after it's warmed up, adjust the idle screw.

 

I want it to idle higher when I have the choke on, right now the idle doesn't change when I engage the choke.

 

The idle isn't meant to change, the choke makes the fuel richer, to get the engine to run until it's warm.

 

Well when I run my bike with the choke on the rpm is the same as when it's off, what do you think is the problem?

 

Does it stay running or do you have to keep pressing the throtle to keep it running? When the choke is on.