Exactly. That's why I was asking OP if they ever figured it out. That engine doesn't have a compression release so valve clearance doesn't matter. That engine is always going to be under full compression. If the valve clearance was too tight that could affect compression but that would lower it and make the engine easier to turn over.
I've seen many starter solenoid issues and also issues with battery cables. They use such small cables on most of these machines that once you get a couple of years on the unit and nothing is as clean as it was new, you just can't get proper voltage to the starter any longer.