DIYbanter - View Single Post

wrote:
I am attempting to help to get a snow thrower working. :-) It is a
Craftsman snow thrower (model 536.884330, code 0323M) that starts and
then after about 15 minutes of running, stalls. Sometimes, we can get
it restarted, but even then it seems to stall every few minutes until
eventually it will not start.

If we wait a little while and come back an hour or so later, it
restarts.

The gas mixture is fresh. What would inhibit it from continuing to
run? Would replacing the spark plug be next on the list or do we need
to look to the carb?

On later model air-cooled engines, this behavior can be caused by an
ignition module that fails when hot. Once the module cools off -- even
for a few minutes -- the engine will run OK for another short period.

You don't even mention what brand the engine is, but every make has
pretty much the same style of solid-state ignition module, and any of
them can develop this problem. It's an absolute ******* to
troubleshoot, because anything else you mess with seems to help -- for a
while. Until the module heats up again and stalls the engine.

Pull the flywheel housing and the module will be right there. It looks
like the magneto of older days. Be prepared for an obscene replacement
cost, which is why I keep several of these lying around for diagnostic
purposes. A scrap mower engine or two can come in handy as a source of
parts.