Small Engines (Lawn Mowers, etc.): B&S 17HP intek, compression power, power stroke

Question
I just replaced the camshaft in the motor because it was worn out and since replaced the rings and all of the gaskets.  tried to start it up and it's popping thru the exhaust and wont start.  checked the valve clerance and it's good.   Im just tring to see if maybe it set the crank to cam timeing wrong... I set the to dots together on the gears just like you do in a car engine.  I couldn't find a repair manual for this engine   Model # 31F707

Answer
Is the flywheel key sheared?  Aligning the dots usually works but another way to check the time is to rotate the engine by hand and follow each stroke; intake, compression, power and exhaust.  Make sure the valves are opening during the correct engine cycle.  For OHV engine, you can use a drinking straw inserted through the spark plug hole to determine if the piston is moving up or down during the engine cycle.

You can also check for valve overlap but this is a bit more difficult to observe on OHV engine.  All 4 cycle engine have valve overlap at the top of the power stroke.  This overlap is a tell tale sign that the mechanical timing is correct.

Let me know if the flywheel key is sheared.

Eric