The drive wheel is spinning despite neutral

[Marqs1979]

I was working on the electrical system and the engine ran , suddenly the rear wheel began to drive foreward despite gearbox was in neutral Guess any chaft is being cut ? Or is this something that can happen when the clutch gets hot ?
I guess I have to disassemble and inspect .

[Greybeard]

Clutch drag I guess.

[Greybeard]

Could thick, (cold) gearbox oil be causing gear drag?

[morris]

Worth to have a look to see if the final gear bush is not to tight on the mainshaft.
Otherwise it's just a case of "They All Do That Sir"...
Both mine do it (though it's more of a creep than a spin)

[Marqs1979]

Hehe :) I will investigate. But I 'm relieved to hear that I am not alone :)

[Triton Thrasher]

Unless you were holding the clutch lever in, this has nothing at all to do with the clutch.

And it's normal and not a problem, unless stopping the rotation with the brake makes the engine stall or strain.

[Clive54bsa]

Marqs, are you able to stop the spinning wheel by applying pressure to the side of the tyre with your foot, shoe on of course?
Clive

[Marqs1979]

Unfortunately, I do not think I can stop the wheel with my foot : / I'll look into it but I not have time before Friday

[Butch (cb)]

Tend to agree that they all do that. But if it seems more seriously driven then I wouldn't be putting my foot on/in there. What happens when the rear brake is applied?

[Triton Thrasher]

Can you spin the wheel, when the engine is stopped?

[Clive54bsa]

Yeah, you're probably right about the foot thing, I suppose the brake application would be more safe. Both my A10's rear wheel spin when the bikes are running on the mainstand, but a bit of friction from my foot stops them from spinning. If that's the case, I'd say you don't have a problem, but after applying the rear brake, the motor stalls or almost stalls, I'd say the sleeve gear on the output shaft of the gearbox was overtightened. A mechanic I know uses an impact wrench to tighten them, I'd not recommend him.
Clive

[Marqs1979]

I have not yet had time to try something more but I think I have a problem, because the motorcycle was stretched on my motorcycle lift and began to go foreward

[Marqs1979]

I might add that the engine and gearbox are refurbished by me and it's not impossible that I have tightened something too hard ?? Or that some bushing is too tight ?

[bsa-bill]

not impossible that I have tightened something too hard ??

My guess would be that neutral is not where it should be,
put the bike in neutral.
remove the outer g/bx cover and check that the red dots on the selector mechanism line up.
If they don't then correct them.
If they do then move the selector one tooth out (which way I can't tell you, it's suck it and see)

This is not uncommon on these box's, I've done it myself

[chaterlea25]

Hi Marqs,
When you rebuilt the transmission did you fit a new sleeve gear bush?
If so how much clearance did you give it?
Did you drill the 3 oil holes?
With a one piece bush its necessary to make a recess half way in the bush, the originals were 2 piece steel backed, the bronze was machined away where the 2 halves meet
Did you fit a nut with an oil seal? (SRM) the older version of these had a smaller diamater seal that was tight on the mainshaft
It is possible to make the end of the high speed gear contract by overtightening the sprocket nut 
This happened to me when using an air impact gun

John