Gas in the carb rules out the cruddy tank option. I'd
suspect heat related problem. Bad ignition coil insulation
comes to mind. Also option of valve seats may be burned, and
the valves aren't completely closing with a hot engine. Much
less likely is burnt to death motor oil.

The diagnosis needed, is to get the engine hot enough to
fail. Pop the spark wire, and check for spark (ask, if you
don't know the procedure). Also check for compression while
the engine is in failure. That will help determine if it's
spark or valve problem.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Eric in North TX" wrote in message
...

I poured a little bit of gas in the carburetor and it
still wouldn't
fire. I spent some time trying to get the hydrostatic
transmission
release lever to disengage so I could push it back into
the garage but
never got that to work so I left it alone for a while.

After a few hours, I went out and it started right up. It
ran good for
15 minutes and then quit again. I left it in the yard
until yesterday

That sounds like a problem I had with a John Deere. It
turned out to
be the fuel tank was full of crap in the sump where the
pickup tube
operates. I had to pull the tank and flush it several times
to fix it,
but now it runs like a deer.