Honda won't kick start.

[Taylor40299]

My sons Honda crf250f will not kick start all of a sudden. It starts easily with a rolling (push)start. It will not stay running unless the choke is on. We have cleaned air filter, and new spark plug. The bike was new to us in Jan 09 and he has being racing it lightly. I'm probably just going to put it in the shop, but if someone thinks I should check something first I would appreciate it.
Thanks,
Tony

 

[whenfoxforks-ruled]

The valves clearance and ap circuit come to mind first.

 

[whizzit]

What is ap circuit? What year is the bike, a 2009?

 

[_JOE_]

Definately sounds like the classic case of tight valve clearances. Takes about an hour to CAREFULLY check the clearances. You'll need a set of feeler guages and a decent torque wrench. Actually changing the shims requires removal of the cam which is a bit more complicated but do-able by someone with a bit of attention to detail and patience.

And AP is an abbreviation for accelerator pump. The ap is in the carb and forces a squirt of fuel up and into the intake tract to aid throttle response. It also works pretty well as a primer for a cold engine. Simply twist the throttle a couple of times and it will put a charge of fuel in the engine to get it to start more easily.

 

[whenfoxforks-ruled]

And a poorly timed ap can hinder starting and operation off idle. "The bike was new to us in 09"? Ohhhh boy, have you seen the hour mark(maintenance schedule) on your top and bottom end?