Young lad bought a 95 klx250r runs 20 mins pipe goes cherry red and problems idling running stock jet 1 1/2 turns out on pilot screw lid is off air breather and a crank breather K&N filter Any body have any ideas?

 

You're running lean. I'm guessing the spark plug is very very light colored (if the electrode is still attached!) Has the pipe been replaced or packing been taken out? Remember, it's all air, fuel, and spark; gotta have the right mix. May need to adjust the screw or (more likely) re-jet. Start with about 5 sizes larger on the pilot. Get it idling correctly, then take it for a run. See how it operates on a hard run. Bring it home, check the plug. Adjust the main jet (only if necessary; you may not have a problem on the top end, but I'm betting it's a bit lean, too.) Increase the main jet by 3-5 sizes, and adjust to taste.
That's where I would start...