Well I posted a long reply but it didn't show up! I'll try again. As I said in first post, your compression is good. I think you have two problems. The oil in your air intake suggests to me that you have a blow head gasket but would not think the compression would be that high, assuming your gage is accurate. Blown head gasket is common on these and typically is between the cylinder and the push rod gallery on the underside, block side, of the gasket. My guess is that the noise you describe is from worn out bearings in the counter balance ass'y and/or worn eccentrics on the crankshaft that the counter balance ass'y runs on. These are part of the crankshaft and are not replaceable. Likewise, the bearings in the counter balance ass'y are not replaceable and the cost of both is prohibitive. This is usually caused by not changing oil often enough. Walt Conner

Land owners east of me and west one west has 5203 only mows 10 acres with it 509 mower does great job but when new fuel filter stopup about 10 hours on meter. One on east he got it feb. 07 5103 his filter stopup to about 20 hours on meter we changed it then fuel pump silnoid would not turn fuel on sometime at starting but retires and start. Took in for repairs fuel system had loader mounted I toldd that if engage ground needed water in rea tire he did not like water in rear tire because mess when flat but with new loader they put water in rear tires but still to lite in rear so we put my box bade on rear to help and it did have better traction. my best advice would be to get tractor and fuel filter at same time drain fuel tank a few times open the drain cock until just fuel coming out. have in sale to add water to rear tires. Now to spend the money for rear wheel weights if going to engage the ground box blade are scoop stop tractor and spin on top ground tamdeen harrow or turnning plow it want move. They are real nice tractor but lite in butt. In some farm magizines there good deal like 2 axle trailer mower box blade post hole digger in one package. I would take into fact 5103 burns less fuel other than that coin toss on power I can't tell which one has less power are more nice tractors.

donc_1966: Thanks for the picture! I really appreciate you doing that --at least I know it can be done. I am certain that is the bolt that comes with the Turbo installation kit. I think you are probably right about replacing pulleys (but maybe just the blade pulley). With the new spacer and turbo pulley just sitting on top of the blade pulley, the turbo pulley sits about an inch higher than the tensioning pulley. I can't imagine that is right. To Theodocius: Trust me, I have read that step hundreds of times --while looking at all the parts I have left-- trying to figure out what I am doing wrong. Sigh, I can almost see my lawn getting longer as I write this. I am going to call the Simplicity service department here in town and see if they can shed any light.

Thanks, got to see the mower today in person, you were spot on with the engine - so I was able to go prepared! I have a question about the steering on the mower tho. When driving straight ahead, the wheel is 'upside down'. IT makes left turns fine. When making a right turn, its a very WIDE right turn. The steering wheel also has to turn nearly 3/4ths of a turn ion either direction before it 'makes contact' and turns the wheels. Steering Sector? Thanks to reading thee wonderful forums, I now know what one looks like and what it does. Is it a PITA to R/R?