Brought as a none runner with blocked carb! and been standing for many years. A sonic clean of the carb, a correct grade and lengh spark plug fitted and tappets checked. There was some ignition of fuel and some great back fires. It was found that the ignition timing was a mile out. It was firing well after top dead centre instead of btdc. So after some ajustments it fired up but with little response from any throttle movement. So it looks like its only a knackered carb and a recommission and another cub will be on the road.
Wish every thing went so easy with my CM91
