Your gonna love this one!!!

Recent rebuild everything shiny new. starts fine for a few days then progressively starts to click click, then wil not start. Investgated a bit and bought some shims. Installed the 40 and seemed to fix the prob. Back to same prob again. Incidently, this issue was present before the rebuild though it would start after a few very diligent tries.

It seems that you are talking about the starter. If you get click,click,click it means you have low voltage (weak battery) or bad connections . Check the power and ground connections on the battery and engine, clean them and put them back on. Charge the battery and see if it starts. You could have a weak or bad battery along with charging system that is not up to par....

Kev