I have a 2009 KLX 250 that I installed a new carburetor in. When the choke is off, the bike runs exactly as it should. The idle is perfect and it revs and rides great. However when the choke is on and I let it idle, it immediately dies. I can hold the throttle open with the choke on and the bike will rev really high as expected, but as soon as I let the throttle go the rpms drop and the bike dies. This is a brand new carburetor so I don't know if some screw needs to be adjusted? Looking for ideas on what to do.

 

Is this a stock CVK carb or an aftermarket unit?

 

It is a stock CVK carburetor.

 

Being a new carb, I'll assume that's all fine. If you are at high elevation, I would expect it to not need the choke/enrichment. It's possible you have a restriction somewhere, maybe a clogged air filter or something like that.

 

If it's rejetted it might be that you don't need the choke except to start. I know my bike will only need choke for about a minute or less in most conditions. Other possibility is that the choke, which is not a real choke but rather an enrichening circuit, the passage might be clogged and need cleaned out... if the carb is used.