I'm working on a pretty tired Craftsman 6.5HP mower and I can't get it to run smoothly unless I push down on the recoil cover while it's running. As soon as I do that, the engine smooths out and sounds good. Lift my hands and the engine revs immediately drop and engine runs rougher and slower until it ultimately dies. I've checked the head bolts - besides being on the front, running horizontally, they were tight. I can't see what would be affected by putting the equivalent of 20-30 pounds on top of the engine.
Thanks in advance for any suggestions you might have.
PS - Carb is not issue (cleaned old one, tried new one, no change), spark plug (ditto), gas (drained, filled with fresh)
Thanks in advance for any suggestions you might have.
PS - Carb is not issue (cleaned old one, tried new one, no change), spark plug (ditto), gas (drained, filled with fresh)