In nearly all of the 7,369 threads on this problem, it is mentioned that there should be a half-moon key on the end of the exhaust cam that aligns with a half-moon slot on the CAS. If the key is missing (broken off), then the CAS can align in one of 8 or so positions, but there is only 1 alignment that will allow the engine to start.Confirm that the key is there first. If it is, then the engine should run - maybe roughly, but it should run.