Small Engines (Lawn Mowers, etc.): engine stalls, vacuum line, vacuum hose

Question
I have a lawn mower model 445677 type 0413 E1 code 050316YG
This summer some times when I would first start  the engine
it would run for about 2o min. and then stop then it would start right up, other times I would have to wait a few min. and it would start and then it might run for an hour before it would stop. sometimes I could make it run longer if I pulled the chock out a little, but after a while it would stop. I thought it might be water in the gas so I draind the tank. blew air threw the lines and new filter, put new gas in the tank and it did the same thing all over again. Could it be in the ignition or magneto?is there a way to test for it? I tested the auto sut off under the carb. and it semed to test ok.  Thanks for any information ... Gene


Answer
It could be the coil breaking down but this is rare.  To check this, the next time it stops have a spark plug wrench and a pair of gloves handy.  Immediately remove the spark plug when it stops and check for spark.

We use an in-line spark tester available at most autoparts stores.  This way we do not have to remove the spark plug and it is faster to check so the engine has very little time to cool.

Have you replaced the spark plugs?  The problem you described is often associated with fouled spark plugs.

You engine shows a fuel pump.  Are the hose in good shape?  The vacuum hose, the only hose not connected the the fuel tank or carb, should not have any cracks or swelling on the ends.

Replace the spark plugs and check the vacuum line on the fuel pump first.
Eric