replying to Sherman, Marc Belanger wrote:
The lawn mower is probably losing spark. It will get good spark if it is cold,
but once hot, one of 3 things could be happening. First, the spark plug could
be filled with crud, and when it is cold, the crud has a lot of non conductive
grease in there. This will turn to a liquid when hot and become conductive
enough to short out the coil pack and kill the spark. I would replace it if it
looks like there is crud between the edge of the steel and the porcelain on
the inside of the spark plug. Look between the metal electrode and follow the
porcelain where you can't see it anymore.. Yeah, thats the place, either clean
it out and get the bl;ack stuff out, eliminating the short and it will
probably work again. if not, the spark plug wire may be cracked and work while
cold, but once it warms up, the break is separated enough not to work. Same
thing with the coil. Or, the coil could be hust loose. It needs a ground to
work and if the coil is loose, when cold it may be connected electrically then
when it warms up it may disconnect. The coil and spark plug wire are one piece
on a tecumseh or briggs and stratton and are less than 25 bucks normally. Get
one, screw it on, wire it and rreplace the spark plug. Then, check to be sure
the shut off wire isn't shorted to metal anywhere, it it is, the mower will
still not start. tape it or reconnect it correctly to fix. The coil is under
the crankcase cover. Oh, btw, the coil needs to be mounted the correct
distance from the flywheel if you never seen one before. Try to line up or
mark the old one before loosening it. Some coild only mount in one location so
this may not matter.

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