Short version: Head gasket on one cylinder is blown. It was reading 0 psi with a compression test. However, the other cylinder was only reading 30 psi. Also, the other day the RPM spiked crazy high (friend suggested governor could be the culprit). Now at half throttle the mower is faster than it was at full throttle. Would replacing the gaskets fix all my problems? What should I be replacing while I have the engine this far apart? Also, below there is a picture where the pushrod was rubbing on the block? and wore in a spot. Is this a big deal? Could there be a crack somewhere? ANY HELP IS GREATLY APPRECIATED! LONGER VERSION: So for months now I've had to use my mower with smoke and a slight amount of oil (enough to get the valve cover and a little bit of the deck dirty) coming out from around one of the valve covers. It would mainly just pop a little smoke when you started it but that was it. THIS IS IMPORTANT> THE ENTIRE TIME IT HAD FULL POWER. SINCE THE DAY I GOT IT LAST YEAR TO NOW, IT HAS THE SAME POWER OUTPUT. I just didnt have time to mess with it so stupidly I kept mowing with it. Yesterday, I was mowing along and the RPMs seemed to spike super high, So i shut it off. I let it cool, then tried starting it again. At that point, at half throttle the mower was operating louder and seemingly higher RPMs than full throttle before. Any idea what that problem could be? Since I wouldnt be able to mow with it with the RPM problem I decided to attack the head problem. First I compression tested it. On the left cylinder that had smoke coming out of it there was no pressure at all. The guage just read 0. Then I tested the right cylinder and got between 25 and 30 psi from it. On this website (http://www.ereplacementparts.com/kawasaki-fh500vas06-stroke-engine-parts-c-30157_30211_31391.html that has good diagrams for my motor, this guy commented this at the bottom " Compression should read min. of 57 psi. to around 95 or 100 psi. " so seemingly something is wrong with both cylinders. I got her all taken apart down to the head and there was an obvious problem with the gasket on the left cylinder that had been smoking which you can see here: You can see where the gasket was blown out at the bottom of the cylinder and if you look closely, another spot to the right of that. If you look around the actual cylinder you can match the gasket up and see the black spots where the oil and what not has been pouring through. You can also see how black the top of the cylinder is. If not here is a somewhat better picture of the area around the cylinder: So does that area that is blown out on the head gasket explain the 0 psi compression? What could be wrong with the other cylinder being only 30 psi? I am wondering if there is possibly a crack in the block somewhere? Also, I noticed that in the following picture, the push-rod on the left cylinder that was smoking, has been wearing into the block a little bit? Is this something to worry about or not a big deal? The push-rod seems to have no wear on it whatsoever. There you can see at the bottom of the big hole in the center where it's all worn out. SO, will replacing the gaskets fix my problem? With the black piston, should I replace anything while I have it this far taken apart (besides gaskets and what not)? A friend mentioned that the high RPM could be the governor but I have no idea where it's located. ANY HELP IS GREATLY APPRECIATED!