gearbox/ kick start lever sticking

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Vincent 42
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Joined: Thu Jul 22, 2021 3:29 pm
Location: Leicestershire UK

gearbox/ kick start lever sticking

Post by Vincent 42 »

have just purchased 1951 18s 500 single, the kickstart travels freely for 2/3 of its movement then sticks and has to be lifted back. before I start to strip is there any comments or advice of possible causes and rectification. thing to look out for thanks. ROD
SPRIDDLER
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Re: gearbox/ kick start lever sticking

Post by SPRIDDLER »

Vincent 42 wrote: Fri Dec 24, 2021 2:00 pm have just purchased 1951 18s 500 single, the kickstart travels freely for 2/3 of its movement then sticks and has to be lifted back. before I start to strip is there any comments or advice of possible causes and rectification. thing to look out for thanks. ROD
Welcome to the forums, Rod. Lovely model!

I assume by 'travels freely' you mean it doesn't engage to turn the engine. If that's so it sounds as though the kickstart pinion may need freeing, especially if the bike has been stood for a while. The sticking k/s lever may just be due to a weak k/s return spring.
Your bike will/should have the Burman CP gearbox.
Have a look at pages 72, 75 and others in the 'Transmission' section of the workshop manual in this link......

http://archives.jampot.dk/book/Workshop ... dition.pdf
'There is a tide in the affairs of men
Which taken at the flood............'
Vincent 42
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Posts: 5
Joined: Thu Jul 22, 2021 3:29 pm
Location: Leicestershire UK

Re: gearbox/ kick start lever sticking

Post by Vincent 42 »

thank for your reply. no the lever works as it should turning the engine for two thirds of it travel and will return as it should and further movement is stiff and the lever has to be lifted to the free point, the bike is fitted with a Burman GB2a L52 . released the screws this morning with the intention of removing the cover trying it again i found odd times it operated freely full travel and some times it would not engage wondering now if kick start lever was not set right and trying to move it beyond it required travel. will have a look at the other pages . by the way have released clutch plates so i can operate it easily
SPRIDDLER
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Re: gearbox/ kick start lever sticking

Post by SPRIDDLER »

Ah, it's a B52 so yours will be a late 1951 bike as the GB52 'box was first introduced for the 1952 models of AJS and Matchless machines which were released after Sept 1st '51.

I can't offer much help from this distance but I recall that some owners have 'cured' a sticking k/s lever by using two gaskets on the outer cover.

However, the following link has several articles on inspecting, stripping and overhauling the B52 'box which may give you some clues.

https://www.jampot.com/article_read.asp?id=20

The k/s quadrant and its engagement is also shown in an illustration on page 10 in the 1952 Owners Manual. Link below.......

http://archives.jampot.dk/book/Owners_m ... Manual.pdf
'There is a tide in the affairs of men
Which taken at the flood............'
Vincent 42
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Joined: Thu Jul 22, 2021 3:29 pm
Location: Leicestershire UK

Re: gearbox/ kick start lever sticking

Post by Vincent 42 »

[ Many thanks , seem to have sorted kick start sticking. quarter turn on screws. but still a pig to kick over even with spark plug removed. will have to find out if the engine has had work done on it by previous owner. I cannot start the engine by kick start only by bumping it then it runs beautifully. but that is no good if i want a run out, have a G12 which is a dream to start and ride. interesting read of the links ROD
SPRIDDLER
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Re: gearbox/ kick start lever sticking

Post by SPRIDDLER »

You've mentioned that you've only just acquired the 500 single so I'll risk suggesting the following which may be unnecessary, but anyway......

Are you adopting the recognised procedure for kickstarting the 500 single? I.e. decompress and bring it just over TDC etc. etc.
The 500 single has a very heavy flywheel with considerable inertia, unlike the G12, plus when you start the twin you are only kicking over one 325cc cylinder at a time.
In colder weather a monograde oil can produce significant oil drag on the long stroke single engines.
The 500 single will have a magneto which unless it's in a perfect state of health will be required to rotate smartly to get a decent spark whereas the the twin may have coil ignition which will give a healthy spark regardless of how fast the engine spins when kickstarting.
'There is a tide in the affairs of men
Which taken at the flood............'
g80csp11
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Re: gearbox/ kick start lever sticking

Post by g80csp11 »

if you don't have correct gaskets fitted on the gearbox , then its possible for clearances on gears to cause drag on gearbox
all too often owners replace gaskets with sealant .
correct new gaskets fitted will not leak if surfaces are cleaned
Vincent 42
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Posts: 5
Joined: Thu Jul 22, 2021 3:29 pm
Location: Leicestershire UK

Re: gearbox/ kick start lever sticking

Post by Vincent 42 »

thanks to everyone that posted a reply belive it or not i found the problem after removing gearbox cover .on removing the kickstart quadrant i found that someone had replaced a cap screw with a spring washer that now was causing the head to fowl the quadrant sorted and replaced cover with thicker gasket ,all good. Rod
56G80S
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Re: gearbox/ kick start lever sticking

Post by 56G80S »

Great result! I'll have to list the odd things I've done on the Matchless, like fitting a stud on the rear oil pump plate where the thread was weak etc.

Johnny B
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