Small Engines (Lawn Mowers, etc.): 12 1/2 HP Briggs ele start, hp briggs, shear pin

Question
Had 2 B&S engines -1 with broken rod. 1 would not start(valve stuck)Blended both together.  Have spark and fuel with new shear pin and valve clearence. Eng turns over about 1/2 turn then hesitates and you have to enguage starter again. With plug removed spins freely.  HELP!

Answer
 Hello Jim Wallace:

 If you Timed the Crankshaft and Piston to the Cam Correctly, then the Valve Clearance is the Problem. The Newer Engines have a Compression Release on the Cam and the Intake Valve is Set to .006in. Hope this Helps. Thanks.

 Good Luck

 Respectfully

 John