See if the blade is loose. It needs the weight of the blade
to push the piston through the TDC.

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


"John Husvar" wrote in message
...
At work we have a Sears mower, about 5 years old. It has a
Tecumseh
engine. On first attempt at using this Spring, it started
backfiring
through the carb and will nearly break your arm when it
pulls the start
handle out of your hand.

We found the flywheel key broken and replaced it with the
correct Sears
Part Number. It still does the same thing, though not quite
as bad.

Magnet to coil clearance is .003. Compression seems good.

Anybody have any ideas? (Well, other than changing the
mechanism under
the nameplate or the nameplate above the mechanism, or both)