Thanks anyway aussietrev.

Met a guy today who came over to look at the bug. He has worked on them over the years. I have had this machine since it was 3 years old. Found out the motor i not the right one. They had a 8.5hp mounted sideways to fit. He said a 198700 series motor? So now trying to find out what machines used the 198700 series, with no luck, but at least it helps. So over this 22mm shaft problem.