Small Engines (Lawn Mowers, etc.): Ariens Snow blower, cub cadet mower, bolt torque

Question
I have an Ariens snow blower that has a problem. It starts right up and runs good for about 20 minutes and then it starts to stumble and finally stalls out. If I hit the primer button when it starts to stumble it revs up normally. I took the carburetor off and cleaned it but it does the same thing. Any ideas you have would be appreciated. Thanks, Art.

Answer
How old is the snowblower?  I once had a really old Cub Cadet mower that did the same thing.  I thought it was carb.  Turned out it was fuel related, but it was a leaking head bolt which caused the head gasket to leak when the engine warmed up.  Very, very rare but it does happen.

Check the intake gaskets and retaining fastners.  I would also check the head bolt torque.

If you have a late model OHV engine I would check the valve clearance as well.

Let me know what you find.

Eric