AJS & Matchless Owners Club

OK, thanks for the advice.
I'll take another look over the next couple of days
Cheers
Mike

Sorted the timing, it was way off.
Now she starts and runs on choke, only letting me reduce the choke after a few minutes.
When ridden, she will only run with about half choke.
Needless to say she pops and bangs on the overrun.
Sounds to me as though she is running very rich, but why won't she run smoothly without choke?
The carb is clean, no blocked jets and I can't see/hear any air leaks.
Any clues, please let me know.
She is still slower that I would have thought, at 45-50 max.
Cheers
Mike

If the spark plug is excessively sooty , try dropping the needle a notch
You should be able to open the choke fully within 1 - 2 minutes at the most
plug colour is still a good indication if everything is OK

I believe popping on overrun (throttle closed) is actually a sign of lean pilot setting. Hence only running well when partially choked. Adjust air mix or change/clean pilot.

Thanks guys
Plug was sooty, so the mix was rich.
I think there were two problems, main jet was not set right, making it difficult to set the air mix at tick over.
Raised the needle one notch, and was able to adjust the air mix.
Choke is off after a couple of minutes.
Now it's just right.
She runs beautifully now.
Hopefully many happy miles.

Hello MikeC,
The difficulty you have in getting a good tick over is not related to the main jet: at tick over and low throttle opening it is the pilot jet that intervenes. It is it who must be checked, and also its circuit. In other words, if the richness screw is not sensitive look at the pilot jet.
Kind regards.

Good to hear its running well now... Do you have some more top speed?

Hi Joker-bones
Yes I have a much better top speed 50-55mph
I've not tried any faster as not enough straight & flat roads nearby.
I'm still getting acquainted with my bike, so everyday is a school day.

Thabks to everyone for your help and suggestions

Mike

Of course you speedo may be misreading , i remember pushing my 1927 H4 SV ( no speedo fitted) on way to Brighton , mate said 57 on the A23 , about a month later conrod through the side ! apparently in 1927 in racing trim it would be 71.25 mph on a race circuit at the Belgium Grand Prix
Perhaps my engine failure was pure considerance or just old age (the bike not me )

My 1961 G3LS with a heavy chap on it is still able to get 71.2mph according to a gps I had in my pocket. But that was making good use of some good Hillary that I have around here. I always giggle when I overtake modern cars that cant seem to make progress on the roads even though they are driving cars some 50 years newer.