What is wrong with my lawn mower?

Question

Briggs and Stratton engine, model # 12Q802 Type 0204.

It runs for 5 minutes and dies like it is out of gas. Sometimes it will crank again for a few seconds if you prime it 10 or more times, sometimes it won't.

Either way, if you let it sit overnight, it will crank up immediately and run for another 5 minutes and the cycle repeats. It will take a month to cut my grass this way.

Answer 1

It could be a clogged gas cap vent, but if that's not it, it may be vapor locking.

Make sure that the fuel line doesn't get too close to hot engine parts. Make sure that any heat shields and/or baffles are in place.

Answer 2

First answer could be right. Or it may need the carb rebuilt, which is a fairly cheap fix. The problem in that scenario would be the needle valve and/or the float. The kit to rebuild it is around $15.

Answer 3

Gas cap vent is clogged. Next time it quites, remove the gas cap and put it back on. Try and start it, if it runs, get a new cap or fix the vent.

Answer 4

i beleive it could be the electronic module in the flywheel,most mowers doesn't use points anymore,ck it out,you can buy everything you need to fix it w/at you parts store.not that hard to do.