I have bought the above engine second hand. Have mounted it inverted in a 1/6 scale Bristol M1 (Balsa USA kit). Motor runs fine on test, but appears to be leaking some fuel from around the prop shaft, which is, I think, the cause of the spinner backplate slipping. The spinner is scale for the model, (bigger than half a tennis ball), aluminum, the backplate is thin brass and doesn't seem to have much grip on the drive flange. So my questions are:
a) do I replace the prop shaft bearing, or
b) could I drill thro the backplate and into the drive flange and tap the two holes for short M4 cap head bolts?
Would appreciate any suggestions, thanks.