Re: Motor Jumping around
Most likely cutch dogs either worn or not adjusted properly. This will make the engine give a loud thump (more often at high throttle settings and less at low; at some low speed point it will not happen). Take the shift linkage and adjust it so you have slightly more down . If that solves the problem, your linkage was out of adjustment. Be careful! too much adjustment and you will not go into reverse.
Sometimes the front of the motor leg where the shift rod is fills with sand or silt and puts too much drag on the linkage. It then will not go fully into gear. Same problem if the shift rod seal swells.
Quick tip: Put the engine in forward gear then spin the prop forward by hand hard with the plug wires disconnected for safety. (this engages the rear faces of the dogs) If it locks up tight and wants to spin the engine against the compression pressure, your adjustment is probably ok and the dogs are probably worn. If it slips out of gear, you are probably not getting enough down throw on the linkage.
