I have a Craftsman lawn tractor #917.27639.
I recently changed the head gasket. It is running fine at the start. After running
Awhile, the engine starts knocking. Most likely it's not getting enough oil to the engine. If it has an oil pump, how can I check if it's working or where the oil is blocked?

Rudy

Make sure the head gasket isn't blocking the oil return hole in the head.

Make sure the head gasket isn't blocking the oil return hole in the head.

That sounds like a logical explanation. I'll check that out. Thanks