Points cam position

Information relating to the Matchless G5 or AJS Model 8 350cc Lightweight
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markthompson59+
Posts: 4
Joined: Tue Dec 29, 2020 10:36 am
Location: Nottinghamshire UK

Points cam position

Post by markthompson59+ »

I have removed the points cam (don't ask me why) but did not take note of the position. The cam can be fitted in two positions i.e. 180 degrees apart. How do I check the cam is in the correct position and not 180 degrees out?
Groily
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Joined: Thu Jul 04, 2002 1:00 am
Location: NORMANDIE FRANCE

Re: Points cam position

Post by Groily »

If this is on a single cyl Mod 8 or similar, then won't you be able to tell by the fact it won't run in the 'wrong' spot?
To confirm where you're at, I'd set the engine a bit before tdc on compression. Both valves shut. (No need to go all precise about it, if the basic timing was ok before.) If the points are opening (or just have or are about to) you're OK. If they're miles off, you're not, and need to move the cam to the other spot.
Should be an easy check, fingers crossed.
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clanger9
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Joined: Sat Jun 20, 2015 9:38 am
Location: Chester, UK

Re: Points cam position

Post by clanger9 »

It doesn't really matter - it'll run fine with the cam (and points plate, of course) 180 degrees out.
The exploded diagram suggests that the correct position is with the condenser towards the bottom. On mine, the points were at the bottom (so 180 degrees out) and I had no problems.
1989 Moto Morini Dart 350
1993 Ducati 750SS
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