Small Engines (Lawn Mowers, etc.): Tecumseh LEV 90-120 engine, stale gas, rotary mower

Question
Toro rotary mower with Tecumseh 4-cycle engine. Engine starts great then quits in about 5-10 seconds. Will re-start immediately but quits again. New air filter. Last used about a week ago and it ran just fine.

Answer
How fresh is the fuel you have in the tank?  IS it fresh from the pump within the last two weeks? Stale gas can cause an erratic problem like this.

Do you have your fuel valve turned to the "ON" position?

Your fuel cap may not be venting properly.  Loosen or remove the cap and then restart the engine.  If it doesn't quit, we figured out the problem....  You need to purchase a new fuel cap.

Send me a followup and let me know what you find

David R