Hey everyone, what I would like to know is if the symptoms my bike is experiencing is due to the carb running lean. It usually takes a good 3-5 mins of cranking to get it to start cold and another couple minutes with the choke on or hit the throttle to stay idle. I have a 06 250 Bruin with stock Mikuni 33mm carb. Could I adjust the carb to make it run richer? once it's warmed up it runs fine.

 

What elevation are you at?

 

I live in Missouri, it's pretty low, not sure on exact feet though

 

One sign of a lean condition is an overheated engine. If its running a bit too hot you might see a glowing red head pipe.

Another sign is a backfire during engine braking or deceleration.

If everything is stock and its running lean, you may have a leak in your air box, or on the intake somewhere before the carb.

The cold starting problem might not have anything to do with a lean condition. Especially a slight lean condition.

 

Ok I inspected the bike and found a slit in the hose that connects from the air box to the carb. I'll try to replace this and see if it runs better.