Have a crafsman riding mower 17hp I think had to put a flywheel on it now it kicks back and and shears off the flywheel key done it twice now?? Any help valves? This thing is only 2 years old not heavy use.? Help me thanks..

Tell us more about the engine and less about Sears. Is this a B&S and is it a V twin. Intek, Vanguard or what

It is a single cylinder. The magnet came off and stopped the fly wheel so I put on a new and flywheel did not wreck the key put it all together turn it over and pops a few times and shears the keyway off.. checked the valves they are not out of adjustment.. timing is off somehow put the old fly wheel back on dose the same thing anything I could check?

This seems like a bent valve. Check the valve clearance. If really bad, suspect bent valve.

I thought you started by saying your replaced the flywheel. Have you removed the flywheel and reinspected that key? The flywheel and magneto set your timing so your problem lays in their alignment.

Yes ty found that I didn't draw flywheel up tight enough and spun on the key

So you are all good now?

Yes works great