Slipping Kickstart

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
Peterlukes12
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Joined: Mon Jun 08, 2020 9:58 pm
Location: Kingston uponThames

Slipping Kickstart

Post by Peterlukes12 »

The Kickstart on my 1956 G80CS has started slipping. The clutch seems fine when the bike is running. I wouldn't want to swear there was no slipping as i haven't done anything really aggressive to test it. But in normal use it seems OK. Any advice tips on where to look first? and likely fixes. The Kickstart itself seems pretty well attached to the shaft and i don't think there is any movement there
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clive
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Re: Slipping Kickstart

Post by clive »

It would help if you could describe you problem a bit more fully. The clutch will slip much more easily when kick starting the bike than during gentle use. One way I test for clutch slip is to put the bike in gear with the engine running and astride it, front brake fully on Rev the engine and gently let the clutch out. Engine should stall. If it's slipping revs will drop then rise again.
clive
if it ain't broke don't fix
Mick D
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Re: Slipping Kickstart

Post by Mick D »

Hi

First thing I'd check would be the clutch adjustment - see page 45 here:

http://archives.jampot.dk/book/Owners_m ... ingles.pdf

Regards Mick
SPRIDDLER
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Re: Slipping Kickstart

Post by SPRIDDLER »

Welcome, Peter.
As said the clutch is most likely to slip when kickstarting as you have to overcome the inertia of the heavy flywheels.
Is the bike new to you?
Assuming that it is correctly adjusted it may be due to weak or incorrectly set springs at the pressure plate. Clutch adjustment is set at the clutch pressure plate. The clutch cable adjuster only adjusts the slack in the cable.
I've no personal proof of this but it's said not to use modern multigrade oil in the chaincase as these oils contain anti-friction additives.
If you don't have them the original Owners and Workshop manuals are accessible here under 'Books':
http://archives.jampot.dk/

( :oops: My post crossed with Mick D's)
'There is a tide in the affairs of men
Which taken at the flood............'
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1608
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Re: Slipping Kickstart

Post by 1608 »

Simplest and easiest thing to check first is to remove the filler/inspection cover on the gearbox and ensure there is some free movement of the
actuating arm, if not then adjust as per the book.
Stan Palmer
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Re: Slipping Kickstart

Post by Stan Palmer »

Mine used to do that. It gradually got worse. Turned out to be the ball in end of the clutch pushrod had worn its way into the anvil at the output of the actuating mechanism. The anvil should be flat. Mine had chewed out a perfect hemisphere, the pushrod was hanging up. The warning is a clicking noise when you withdraw the clutch (though that can also indicate problems in the three ball plate).
Stan
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clive
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Re: Slipping Kickstart

Post by clive »

I think the clicking noise is a symiptom on the Burman B52 box. A 56 bike would have the AMC box possibly.
clive
if it ain't broke don't fix
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1608
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Re: Slipping Kickstart

Post by 1608 »

Thats why I wasn't box manufacturer specific.
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ajscomboman
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Re: Slipping Kickstart

Post by ajscomboman »

clive wrote:I think the clicking noise is a symiptom on the Burman B52 box. A 56 bike would have the AMC box possibly.
Correct if was made from Sept onwards as it'd be a 57 model.
Peterlukes12
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Joined: Mon Jun 08, 2020 9:58 pm
Location: Kingston uponThames

Re: Slipping Kickstart

Post by Peterlukes12 »

Thanks all for the replies and links to some resources. In terms of description, in essence, when i kick the kickstart lever with quite moderate force it doesn't seem to turn the engine. (I'm in the usual past compression part of the stroke).

There are a few things here for me to try, and some reading to do too.

Ive had the bike for a while (2-years), but have put shamefully few miles on it as a result of one or two problems (Magneto, Carburetor), so to all intents it is "new to me". I will try a look through the manuals as recommended, a chain case oil change, inspection, adjustment and let you know how i get on.

best wishes all
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