A friend of my wife asked me to look at her mower because it wouldn't start and she said that when it had started previously, it had no power to one side of the rear wheels. I checked the tank, the gas looked old and had some water in it, so I drained the tank and put in some fresh gas. When I went to start it, it damn near took my arm off because it kicked back to violently. I did manage to get it to run. It ran rough at first, then smoked for a couple of minutes and then it smoothed out and the smoke cleared up and it sounded pretty good. I ran it for about 15 minutes and it seemed to be fine. I then got around the checking the rear wheels and found she was missing a drive pin from one of the drive cogs, so I ordered a pin. Got the new pin and installed it and then went to start it and it almost took my arm off again and now it won't start. It's got spark and it's got fuel. I checked the valves and they seem to be retracting all the way with no excess clearance. Thinking maybe it had somehow sheared the key in the shaft at the flywheel, I pulled the flywheel. The shaft and key were fine. I put it back together. Still tries to take my arm off, like it's firing at the beginning of the compression stroke and turning in reverse, thus grabbing the starter sprags. Baffled.
Is it possible for one of these engines to jump time down in the crankcase? If so, wouldn't that mean something down there is screwed. Before I pull the motor, flip it and pull the bottom off to check it, I figured I'd ask here since I'd never heard of a lawn mower engine with timing gears jumping time.
Is it possible for one of these engines to jump time down in the crankcase? If so, wouldn't that mean something down there is screwed. Before I pull the motor, flip it and pull the bottom off to check it, I figured I'd ask here since I'd never heard of a lawn mower engine with timing gears jumping time.