I just wanted to confirm my opinion on this one.
John Deere LT155
MOL 155B046736
Unfortunately, I can't locate numbers on the engine. I think it's a Briggs but there are no numbers on the valve cover. Appears to be a 15HP OHV. I don't think most of you will need the engine numbers for this question but if you do, I'll try to chase them down. A friend brought it to me and it is in rough shape. Dirt caked in the cooling fins, mouse nest, the works. Some of the fins corroded down to thin metal, chewed through wiring and fuel line.
It doesn't run, obviously. I spin the flywheel and notice it's way to easy. So I find TDC and do a leak down. I put about 90lbs in without even bracing the flywheel and the other gauge reads like 9lbs. So thinking I'm not at TDC, while charging the cylinder with 90lbs, I turn the flywheel through all cycles. The flywheel spins easily with one hand with 90lbs going in.
I can hear the air switch from the carb, to the exhaust and to the sump with the dipstick off. My only thought is that I would have expected way more air and noise to be coming out of the dipstick during the compression stroke. So I was wondering, could this be as simple as a stuck exhaust valve? Or some other valve issue? I soaked the valve cover bolts with PB and am waiting to remove it. As it is, one of the valve cover bolts was already broken off and the others won't budge.