Small Engines (Lawn Mowers, etc.): Toro Lawn Mower Dies after easy start and running for several minutes., lawn mower, spark plug

Question
Hi Eric,

I have a self-propelled Toro 20320 lawn mower. It has run well for a while but I began having problems last year. The mower starts up on the 1st or 2nd pull every time I pull it out of the garage. The problem is when I am about 10 minutes (the time varies) into cutting the lawn it just dies. Then I try to start it up again and it won't even sound like it wants to run again. If I wait for 15 minutes it usually starts right up again. But then it sometimes dies a few minutes later or lets me finish the lawn.

I noticed that playing with the carb intake makes some differences that may allow me to start it after pulling it for a couple minutes. I had it completely serviced in early 2003 so all the basics seem to be taken care of.  

Answer
It is possible to have a leaky intake gasket; I would check the screws/bolts for tightness.

Spark plugs can also cause the same problem, in fact it is quite common for a spark plug to exhibit your symptoms.  I would replace the spark plug and see what happens.

Let me know what happens.
Eric