Concentric Carb Settings - 1956 G3LS

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
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chappers1962
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Concentric Carb Settings - 1956 G3LS

Post by chappers1962 »

I've just got back on the road a 1956 G3LS. It's fitted with an Amal 626 L301, which came with the bike. It's 40 years since I've messed about with carbs, so I'm very rusty but building my knowledge reading the downloads from the Amal site. Had cleaned the internals and fitted new gaskets, but will now replace the needle, needle jet and main jet to eliminate any issues due to ware.

The needle jet is currently set in no 1 position (from the top), but the spark plug is still looking a bit dark (not black, but still not optimum against a colour chart). The bike starts fine from cold, seams to run OK, a little more difficult to start from warm (mag Ok). I don't have the experience to know whether this old brit bike runs optimally or not as having ridden new Honda's for many years.

Daft Question 1. How can you check the main pilot which is from 3/4 to fully open, while I'm running in the bike and therefore keeping revs low?

Question 2. I will be dismantling the carb this week to put in a new needle. What size should the needle jet and main jet be with this carb?

Many thanks
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dave16mct
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Re: Concentric Carb Settings - 1956 G3LS

Post by dave16mct »

Use the same settings as for a monobloc except increase main jet size by 20%. Find the original settings in the 1956 manual : http://archives.jampot.dk/book/Owners_m ... ingles.pdf
Dave
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ajscomboman
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Re: Concentric Carb Settings - 1956 G3LS

Post by ajscomboman »

dave16mct wrote:Use the same settings as for a monobloc except increase main jet size by 20%. Find the original settings in the 1956 manual : http://archives.jampot.dk/book/Owners_m ... ingles.pdf
Dave
I think you'll find it should be decrease by 20% Dave, it'll run real rich going the other way. :)
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chappers1962
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Re: Concentric Carb Settings - 1956 G3LS

Post by chappers1962 »

Thats great - many thanks
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