I have a 1989 mercury 35 horse tiller, manual start. It is a clean motor. Once it is running, it runs great. It idles down nice and low, has plenty of zip on the top end, and THEN will start on the first pull of the rope. The problem is this. To get it started the first time of the day, the rope is just about impossible to pull. I am plenty strong. If I don't have the hydraulic assist lift locked, the motor will actually jump halfway up when pulling the rope. When I pull the rope, I only get one or 2 revolutions and then it just flat stops. I actually threw my back out pretty badly last fall trying to start it. Now, some of you will say that a 35 is an awful lot of motor to rope start, BUT, I used to have a 70 hp mercury and it would rope start fairly easily. Here's the part that baffles. When both spark plugs are out, the rope pulls with the ease that I would expect. Everything turns over easily, I can hear the pop, pop, pop of air going through the motor and exhaust, and the rope recoils nicely back into the motor. BUT, if I take one spark plug and put it in just 2 turns of the threads, the rope immediately becomes almost impossible to pull. That one spark plug is not in far enough to be hitting anything, the spark plugs are correct and are not too long to be hitting anything. When only one spark plug is in and only turned in 2 turns, it is by far NOT airtight, so really high compression could not be the issue.
ANY IDEAS?
ANY IDEAS?