Metal rubbish Magneto flywheel

[Peter Rozenveld]

The crankshaft key from the magnet flywheel breaks a several times. At this time there is a lot of backlash . Thus we used locktite. after several tests , the motors slows down and stops . The ignition is off time (several times) and we take off the flywheel . We found a lot of metal rubbish, The crankshaft keyhole is completely broken . What causes that the key every time brakes. (the engine doesn't run smoothly at full throttle ) and now the crankshaft is completely broken. We can do two things : new crankshaft and flywheel or weld the flywheel onto the crankshaft and that will be finally no access to the contact breakers...
I adjust the float from the carburettor it's now 30 mm instead of 27 mm (it should be 31mm +/- 2mm) but at full throttle it sound like a 4 stroke instead of a 2 stroke...
Please, some help will be useful, and correct my English...try it to translate this in dutch...