Small Engines (Lawn Mowers, etc.): 12.5hp B&S, drinking straw, plug hole

Question
When you removed the carb did you move or loosen the govern arm or retaining bolt?

Can you insert a drinking straw or WD-40 straw in the spark plug hole to see if the piston is moving as you rotate the engine by hand? You will have angle the straw a little to get it into the cylinder. You can use a flashlight and sometimes can see the piston move inside the cylinder.

Let me know if the piston is moving.
Eric
the piston is moving. does that mean it's a valve problem???

Answer
I would suspect a valve problem if you feel or see the piston moving.  The racing engine is the first thing to deal with.

Take a look at the link below and make sure you follow the static governor ajustment procedure.

http://www.briggsandstratton.com/support/frequently-asked-questions/Adjusting%20

Let me know if it starts after the static governor adjustment.

Eric