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Nate Nagel

wrote:
On Mon, 11 May 2009 21:29:45 -0500, Steve Barker
wrote:

Ulysses wrote:
"Jeffy3" wrote in message
...
We have a rear bagger mulching push mower. I accidentally ran over a
very thick tree route and it literally knocked the blade right off. I
was able to put the blade back on and when I manually turn it it
freely spins around but when I try to start the mower it won't start,
it makes a loud clunking sound and the pull rope sometimes only comes
out about half way and abruptly stops. Anyone have any conjecture as
to the nature of the repair and whether it would be less costly to
just get a new mower for a couple hundred bucks?
It seems very likely that you broke the "shear pin" that holds the flywheel
to the crankshaft and keeps it in place. You need a puller to remove the
flywheel. Don't pound on it with a hammer or you might break it or damage
the magnet. Once you get the flywheel off you may find, as someone else
pointed out, that it has other damage too. New shear pins are usually
available at hardware stores in the lawn mower parts section.

shear pin, (which they don't have) won't keep it from turning.
But the flywheel key being sheared CAN make cranking it with the
ignition on a challenge. (spark occurs with the piston just over half
way up - yank the cord right out of your hand

agreed, this is a common failure with Tecumseh engines. I had a handful
of Tecumseh flywheel keys on a shelf in my garage when I lived in
Michigan. My neighbor/landlord was always bringing his mower over for
me to fix and it was always the same failure, I guess they were hard on
mowers/never picked up all the rocks in their yard/mowed right over
roots and stumps. Inevitably it was the flywheel key (a soft metal key
on those, not a pin) the reason it won't start is because the trigger
for the ignition is on the flywheel, once the flywheel spins on the
crank the engine is out of time. Starts running bad the first time you
hit something and if you hit another something it'll knock it so far out
that it won't start anymore... symptoms exactly like the OP's. Kicks
back when you start, etc. (because the timing is too far advanced for
the engine to run)

The fact that I could "fix" lawnmowers and was able to repair a busted
window and "restore" (really just strip off years of sloppy painting and
re-clear) the old brass door hardware got me loads of brownie points. I
think I also tarred the cracks in the sidewalk so the weeds wouldn't
grow up through, edged the walk, weeded the flower beds (actually I
usually just threw my grass clippings in them and then only pulled up
the weeds that managed to get through all that,) and did a couple other
little things and my landlord was just blown away. Makes you wonder
what the average tenant was like...?

nate

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