- Nov 20, 2004
Al,Tulsaalva said:Meriden, in the meantime, had developed a three chambered pump which was intended to produce higher oil pressure. An attempt was made to retro-fit all the bikes we sold with the new pump but I don't know if our Bonny got the upgrade or not. I soon will.
Thanks for the interesting Meriden anecdote!
The only upgrade the factory made to the oil pump that I'm aware of, was a new (71-7317) four valve pump introduced for 1980 that had two extra exhaust ball valves?
A small amount of metal has to be removed from the inside of the timing cover in order to fit the four valve pump in place of the original two valve pump.
http://www.britishcycle.com/Products/tr ... _pumps.htm