Hi.
Thinking about this and trying to apply a little logic, I would think that because the distributor spins at engine speed on the Scott, and at half engine speed on the Sunbeam S7 and S8, the springs would need to be stronger, or the bob-weights lighter, on the Scott in order to prevent the distributor going onto full advance too soon. I’ve just pulled that thought from the grey matter in my brain, and perhaps I am mistaken in that little theory, but I don’t think that the springs from Stewart Engineering would cost much, and maybe it is a case of buying them, fitting them, and then trying the bike to see how it behaves. I have always found that longstroke Scott engines seem to be very unfussy about ignition advance and retard, unlike shortstroke engines, which react well to magneto control. I therefore suspect that the bike will run perfectly well with virtually any of the various grades of spring that used to be available!
Somewhere, (can’t find it at the moment), I have a Scott/Lucas leaflet printed in 1950, which gives all the relevant data for the DKX2A distributor, including the revs at which full advance should be attained. When I find it I will post the details on this website. Armed with that information, you could then hook up the bike to a garage test machine , Crypton, Souriau, or similar, and see just exactly what is happening with the distributor as the revs increase.
However I suspect that even if the distributor was fixed onto full advance, you would be perfectly happy with how it runs….
It should also be noted that a virtually identical distributor, but fitted with a four cylinder type cam and cap, was fitted to countless prewar cars in the UK, notably the Ford Model Y “Tudor”,and late model Austin Sevens, and I’m sure that various vintage/classic car spares specialists could also supply these springs.
I hope that my rambling will help you!
Best wishes,
Brian
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