my lawn mower craftsman 6.5hp 22" over heats were exaust shoots out . what are some common problems that might cause this?

A burnt exhaust valve that refuses to seat / seal itself. So the hot exhaust gases are leaking past. Sometimes they can get cherry red hot.

Update: Lets back up for a minute. By any chance did you run over something, like a rock? If the "KEY-WAY" was damaged the timing could be a little retarded, almost firing on the exhaust stroke. Then cherry red exhaust pipe.

Double check is the right oil, designed for a lawnmower. Completely clean out the cooling fins of any debris and dried material.

Is it running too fast?

How old is this thing?

The muffler could be bad/damaged/rusted out so exhaust is not exiting properly.

Incorrect fuel air mix can cause localised overheating. Try to richen the mixture slightly.

It's probably running to lean.