Hi folks, this is partly a question for Magnetoman or anyone else who may have fitted an adjustable magneto pinion:
Unlike the original, the variable pinion boss is not chamfered, so I was wondering if you fitted any sort of material between the pinion & case to try to stem the seepage of oil.
My timing cover has the original type (useless) felt washer and metal retainer between mag and case, but nothing between pinion and case, also nothing over the taper to impede oil ingress to the magneto. I have bought a rubber washer to replace the felt; Waller talks about fitting a "velumoid or similar material circular washer over the armature spindle...". No mention if anything between pinion & cover though.
I'd like to do what I can to reduce leakage before fitting the adjustable pinion, so would appreciate any guidance. Cheers, Bevan
I'd like to do what I can to reduce leakage before fitting the adjustable pinion, so would appreciate any guidance.
The oil leaking past the bush into the timing case on mine was excessive so I machined a holder for a thin oil seal that I clamped to a boss using a setscrew, as can be seen in the photograph. This stopped all leakage into the case for the entire ~3000 miles. The small pool of oil you see in the photo isn't from the engine, rather is from the chain lube I applied at the end of every ~300-mile day. Anyway, as a result of the oil seal the case stayed completely dry so I didn't have to worry about having a seal of any type for the magneto.
O.K., thanks for that. I had wrongly presumed that the inner primary cases on Ariels as old as yours would have had an opening to the crankcase above the mounting boss shown in your picture, as the later singles do, so I guess the opportunity for oil leaks is less anyway. Cheers, Bevan