clutch basket rattle

pete
is it correct that the valves etc can cause backfiring issues if not working correctly

Photo of the plate that blocks the reed hole

Or a Canadian model which also did not come with the reed valves (at least the earlier models didn't)

If your valves are not adjusted correctly it can cause all kind of running problems including backfire.
I suggest a compression test too just to make sure you have no leaks.
Pete F

This is what caused my clutch basket rattle, bearing wore out on the end of the secondary shaft, yours won't be as bad as that