G15 poor running still driving me mad

Information relating to the Matchless G15 or AJS Model 33 750cc twin. This also includes the G15 Mk II and the G15/45
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StuartN
Posts: 15
Joined: Thu Apr 28, 2005 1:00 am
Location: HERTS UK

G15 poor running still driving me mad

Post by StuartN »

I am slowly getting to grips with my new G15. For those that have followed the previous correspondence this is what I have done:
A new battery has made starting easier. The old one was not holding a charge properly.
The bike wet sumps. I have relapped the pump carefully but it still collects too much oil after running and standing. I will either resort to straight 50 oil or have the timing case modified by Norvil as per Commandos. Anyway I am not concerned about this at the moment it is the poor running that is driving me mad.
I have checked out the carbs. They were perfectly clean and the bike doesn't have dodgy pipes or a rusty tank.
I have checked the ignition system out. It is running with a Lucas Rita not Boyer as I stated previously. I have not yet timed it as I suspect the demon is elsewhere.
The bike now starts easily, ticks over cleanly and runs well but it won't run over 65mph. At 55 it starts to get a bit troubled. I initially thought it was fuel starvation but I can't find a cause. Running otherwise is fine so I doubt ignition.
Has anyone met this before. I know I'm missing something but what!

lawrence
Posts: 2453
Joined: Mon Jan 01, 2001 12:00 am
Location: NORTHAMPTONSHIRE UK

G15 poor running still driving me mad

Post by lawrence »

I don't know anything about the Lucas Rita but on the Boyer if you have a poor connection in the ignition circuit ANYWHERE it acts as a rev limiter. Boyer told me there are 17 connections in the ignition circuit on my Bonnie so there is plenty of scope for checking [:(]

Lawrence [}:)]
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TommoT
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Posts: 1602
Joined: Mon Jan 01, 1990 12:00 am
Location: DENMARK

G15 poor running still driving me mad

Post by TommoT »

Just a quick one: if the exhaust system is new, check that its not restricted somewhere. I have heard about pipes being blocked, silencers completely silenced, etc.. If some kind of blockage exists it will have exactly the effect you describe, and in addition it will run a little hot on the exhaust side.

Lets hear what you find out, when you do, if you do, etc.!

Regards,
TommoT

Ride Your Motorcycle As If Your Life Depended On It - Cos' It Does!
StuartN
Posts: 15
Joined: Thu Apr 28, 2005 1:00 am
Location: HERTS UK

G15 poor running still driving me mad

Post by StuartN »

I've fixed it but I don't know how as I went through everything again before starting up. I checked the carbs again to find one slide sticking but I don't see how that would have caused it. I refilled petrol tank but the fuel was not old previously. I also checked the high tension leads but couldn't find anything amiss. Anyway bike now runs sweetly and I shall try to rack up some miles.

itma
Posts: 7721
Joined: Tue Nov 22, 2005 6:01 pm
Location: UK

G15 poor running still driving me mad

Post by itma »

iffy suppressor caps come to mind as worth investigating perhaps?
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