I need ideas from people who know these quads. I fire it up and ride it about 500 feet and it dies. The exhaust gets extremely hot quick. When it cools down you can start it right back up. My thoughts are a bad valve but I have been told electrical, cam, or carb. The guy I bought it form in early spring said it needs the carb gone through but it rode so fine through the summer?? Have you got any ideas or ever had this happen??

 

I would say it is the carb, it may be jetted too rich causing it to run hot.

 

Check your fuel filter.

 

SOUNDS LIKE THE CDI ON THE SIDE OF THE HEAD IS NOT TIMED RIGHT .

 

The 250x doesnt have an adjustable pulse generator like the older atvs did.

 

Also check your fuel tank vent hose and cap to make sure they aren't obstructed. You may want to check your gas for water conamination too, since it's been around freezing lately. Bring a spare known good plug with you on your test ride, and check for spark immediately when it dies. If it has spark, you can eliminate the ignition as being the problem.

 

sonds like its running lean to me and just needs to be rejeted when it gets colder outside the air gets thiner

 

Sounds lean to me too.
when it gets cold outside the air gets denser and has higher oxygen content therfore causing an unballanced fuel/air ratio (more air than fuel) hence a lean condition.
If you run it lean too long you will have a valve problem.

 

If he had a jetting problem I seriously doubt he would make it 5 feet not 500. And colder air is not thinner it is denser.