Join the dots

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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spookefoote1956
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Join the dots

Post by spookefoote1956 »

Hello as a part of my timing education can anyone explain why the timing dots for pre 1956 500 ajs/match are 2 and 2 and 1956 on 2 and 1. What I don't get is that the engine for a 47 is the same as a 56 so why the difference.

Is Ken De Groome right in his approach that the numbers don't matter and that we should use the dots nearest to the 2 o'clock for inlet and 10 o'clock for exhaust?
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
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clive
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Re: Join the dots

Post by clive »

Part of the answer depends on whether the mag is in front or behind the barrel. With the mag behind the barrel the inlet and exhaust cams are reversed.
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burrage
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Re: Join the dots

Post by burrage »

In 1956 the same marks as 1955 were used but the numbers were swapped over, so that the dot previously labelled 1 became 2 and the dot previously numbered 2 became 1. See my article in Jampot January 2001.
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