My yz250f is running real hot and wont idle wright

Even when I run my bike pipe is so hot cant ride safely as I have to lift my leg out of the way bc pipe is burning hot. Without touching it already have burn scars on my leg.

If you have changed the jets you may have to try a different size. I suspect that the pipe is getting red hot from to much fuel . I think your problem is the choke. It may be sticking, have a bad plunger, or may not be closing all the way. Start your inspection there.

The cooling system on the RM-Z450 was designed for motocross and only works efficiently with air flowing through the radiator. You should not sit at idle for more than a minute or two if at all possible. The extreme high output of this engine causes extremely high exhaust output temperature. The pipe temps can reach 600-800 degrees F plus all the way back to the silencer. This is normal on all modern racing 4-strokes. There are a lot of aftermarket products available that help increase the cooling system efficiency. There are also several products that help insulate critical areas from engine and exhaust heat including shields for fuel tanks/lines, the carb/throttle body, rear shock, and plastic body work.

Any reason you had to change the jetting??New pipe,Intakes.?But,even though you may have it a bit rich on idle the pipes WILL get very hot,very quickly without some sort of air flow over the front of the motor and radiator.At the very least,have a strong fan blowing directly on the front of the motor if you are going to let the bike run and you are not riding it.I have seen the white plastics in front of the radiator distort from the radiant heat.Don't idle them for in more then 20 seconds.It can do heaps of damage.Ride the bike and see if its running well.When you stop,turn it off.All the yz and wrf will get very hot at idle.Hope this helps