Hi
I have 04 kfx250f bought 2nd hand from dealer (x demo) has 80hs on the clock currently & top end was done at 60hrs.The bike is stock and I do mostly trail rides and I have had no promblems with this bike thus far.
I service the bike every five hours (oil,filter,air filter etc...).
The promblem is the bike will not idle at rest even when hot as I rode for serveral hours today and I have tried adjusting idle switch but then idles way too high causing over heating very quickly and bike is difficult to start now normally 2-3 kicks.I had just serviced the bike before I rode and did nothing different to what I normally do any suggestions?

First check the hot start plunger and make sure it is not stuck partially open. Make sure there is a small amount of slack in the hot start cable. A large amount of slack could indicate it is stuck open causing the bike to lean out at idle. Clean and lube the plunger with some NeverSeize.

If that ain't it: Check the valve clearance, especially the left intake, check for trash in the bowl and the pilot jet circuit. Install a #42 pilot and a T handle fuel screw.