On Fri, 23 Dec 2011 15:56:55 -0500, Bob Engelhardt
wrote:

jim wrote:

What he was describing was the ignition timing being advanced so that it
causes kick-back and that is what would shear the key. ...

OK, that makes sense. I was thinking that the points themselves caused
it & I was having a hard time seeing how that could be.

Some of these small engines have a compression release on the exhaust
valve train to lower the compression enough to crank it. You have to
know the factory way to adjust the exhaust valve to allow for this or
the compression plus ignition kickback is nasty.
One Briggs, you have to find tdc piston on the fire stroke then turn
past tdc for a certain piston drop then set the exhaust valve
clearance there. Maybe some similar trick on your engine.
--
Mr.E