G: Gearbox (Single - Burman) Burman Gearbox advice needed.

timetraveller

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decomp' cable can be used as 'get you home' repair, have done so and think it is pointed out in one of 'the books'.
Only on the twins, not on the Comet.
 

Peter Holmes

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I think what Norman was pointing out was on a twin the two cables, clutch and decompression are essentially identical, not so on the single, the nipple at the clutch actuating lever is different, but from what you say, not withstanding the difference, you made it work, handy tip to know.
 

Martyn Goodwin

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I would go with Simon on this as I had the same thing happen to my Comet and found that the splines had gone.
I have had EXACTLY that problem, not once, but twice with my Comet. Gearbox drive sprockets had NOT been hardened.

Also can be caused by the drive sprocket nut not being securely tightened allowing it to move ever so slightly then 'worrying' away at the splines on the sprocket. Can even damage the splines on the gearbox output gear shaft.

The give away is that you can kick start the motor, you can change gears but nothing happens at the back wheel - its just like a broken drive chain - till you wake up that the drive chain is intact.
 
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BigEd

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Not directly Vincent related but:
Some years ago, when I had my BMW R75/6 I rode from Oxford back to Leicestershire without being able to use the clutch.
From stationary, this involved paddling in neutral with the engine running and crunching it into gear. Junctions were particularly tricky and required a lot of anticipation to avoid having to actually stop if at all possible.
Having my wife on the pillion didn't make it any easier.:eek:
On my Rapide I have a spare clutch cable taped alongside the one in use. Highly recommended.
 

Bill Thomas

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If you take the clutch off T.T, There are two big washers each side of the Drum , To hold the rollers together,
One is thicker than the other, I think the thick one is behind the drum, Closest to the gear box ?.
Good Luck, Bill.
 

timetraveller

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OK Chaps. Thank you very much for the advice. I will now pass all that on to Jason. I have got to the state where I do not want to kneel on the floor to dismantle bikes, I have lifiting work benches, so 'young' Jason will have to do the preliminary work. It looks as though the sequence should be as follow; drain the primary chain case. remove left hand foot rest hanger, remove outer cover, remove clutch paying attention to Bill's advice, remove inner chaincase and then inspect the final drive sprocket and gearbox main shaft. If this is correct then I will send him all the above postings and these instructions. Once again, thank you to all who have responded. Unfortuataley there are no Comet owners locally who I could have approached.
 
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Bill Thomas

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I know the feeling, I am not good at rolling around on the floor,
But, I think it's a job for an older chap !, With good tools !.
If you take the inner case off, I think the engine will have to be supported,
Hope the gearbox nut is not too tight, But will have to go back tight as Martyn has said,
There are a few tricky bit's to do, I guess we all have to learn, But I think He will need help.
 

Bill Thomas

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The engine shocker will have to come
Off. I would use a chain wrench to stop the engine turning while undoing the nut.
I put the chain wrench around the body of the shocker.
 
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