YZ250F PITA Hot & Cold Start

 '06 YZ-250 is a 7-10 crank start when cold and often a 10-15 minutes+ start
when hot. Often have to let it sit for awhile, especially if I don't try to
re-start it with a few seconds of it shutting down.

My tech thinks it's the pilot jet but I've read online that it could be
tight valves needing adjustment. The tech's history with YZ250F valves is
favorable and he thinks it unlikely.

Thoughts?

 On 8/27/2011 5:02 PM, Schmoe wrote:

Sounds like tight valves... Take the cover off and buy a 5 dollar feeler
guage and save yourself a bunch of money... If it's like the Suzuki, you
take off the tank, the shrouds, and two screws on the valve cover
gasket... and your in.

 

The history of the bike doesn't matter unless you've checked them recently.  
Like Mr. Tosk said, it's very easy to check them.  You have to eliminate
that first.  I'd do a compression check next.

 
Follow up... carb already had a 48 pilot jet so it was opened up a little
further. It might have a little clog in it. Changed the plug. Checked the
valves. MUCH better now. Though it seems I've lost a little on the bottom
end. Still had enough to toss me off yesterday and remind me that things
hurt when that happens.

 
Oh yeah, the idle screw was 4 turns in.