Hi Paul and GM Gadge
I feel I can hazard a guess ...
The difference in mixtures was because of the variances between
suction lift and gravity feed systems.
Having a 'lighter mixture' [oil is heavier than petrol] ratio
compensated for the loss of gravity in a tank mounted lower than
the carby in the 4G; but higher than the carby in the 5G.
I feel this is why the P1 is so temperamental: it relies on the
condition of good suction produced via sealing of the piston
(good rings and piston/bore clearance)) and sealing of the
crankcase (good crankcase seals).
Paul, your question as to ratio: run the higher ratio (less oil) - 24:1.
I hope that is a reasonable point.
------------------------------------
Jack
