Theres probably around 1cm play in the cutter chain. A little more in the others at the moment. I finished assembly today and started the motor. It struggled to stay running until I fiddled with the throttle linkage. I still haven't had a good crack at the carb settings as I was making sure the clutch was disengaging and engaging correctly at the time. However, when I went to switch it off, i received a decent jolt. I believe it happened as I moved the off switch onto the spark plug. This as never happened to me before when testing or turning off the motor, so what could explain this? The only thing I did was clean the carb, cylinder and replace the original coil with a magnetron coil...Is there a guide to follow to reinstall the head bolts to this motor? Perhaps I've mismatched a bolt or two? Would that cause a shock?