I wholly concur withs Jim's modifications and carry out very similar myself. The o rings are well worth while, if you set a crankcase up with a reservoir of kero and run the oil pump it is amazing to witness how much escapes around the cam bushes. I is also well worth noting that as Mike Forest told us all those years ago the jets often do not squirt quite where they are pointing so the paraffin in your boots alignment method is very worth while.

Location: NZ

Thank you for the reply Jim,
what size hole did you drill through the m5 screw?

Location: Deepest darkest Kent

I reduce the hole to 5/32" with no ill effect to the timing gears or bearing, I would expect you could probably reduce further still.

Location: NZ

Location: Poland

This is a fascinating side-line that deserves a thread of its own with diagrams etc if any of the authorities who contributed to it are willing. Obviously guys like me just go for big pumps and hope for the best !

Location: Ferring, Worthing, West Sussex