It make much more sense to post the engine specifics, since it's an engine problem.
Things like what BRAND.

Direct email answered.

Walt Conner

I too have this same mower with this same problem.I'd like to fix it... is it worth it and how do I get 'er done...?

I too have this same mower with this same problem.I'd like to fix it... is it worth it and how do I get 'er done...?

Here is what seems to have work for me:
I removed the head with the slipped valve guide from the engine. Removed the valve spring, and valve. Pressed the valve guide back into it's proper position (1/8" above the surface of the guide boss on the head). Once it is the correct position, you will see about 1/8" of the guide exposed by looking in through the exhaust port. I then clamped the head to a welding table for stability and grounding. Then layed the wire from my mig welder against the exposed guide protruding into the exhaust chamber and then pressed the trigger on the mig for about 1 second. This will put a deposit of weld on the guide, which keeps it from ever going back toward the rocker arm again.

I don't work on these filthy things, but I think peening with a center punch is the "standard" method.

This mower that I purchased was "peened" or "staked" by the dealer twice before the neighbor sold it to me. It didn't hold either time.