Dynamo drive slipping

[barry2]

Hi Mates
this is my first post, I'm Barry from Western Australia , just bought a 1954 RR A10, the dynamo seems to be slipping , not striped it down yet,   i must I think be a belt conversion, do they have special oil resistant belt's?
Barry

[beezermacc]

The belt conversions are usually toothed belt type so it shouldn't slip. However there are some V-belt types around which I would recommend swapping for a toothed type. SRM sell a toothed type but still recommend putting grease in the cavity.

[Greybeard]

 

[coater87]

 Welcome Barry

 I think we could guess all day, and not get it right.

 Popping the outer timing cover off is not an in-depth job at all. You will get to know your new bike better, and we will find out exactly whats happening inside there.

 Lee

[duTch]

 Whether it's sprockets & chain or a belt, the sprockets/pulleys  are on tapers,  but can't remember if they have woodruff keys or not.  Either way maybe the keys are not there and a sprocket/pulley is slipping on the taper/s...

[morris]

 

Could be just de nut from one of the pulleys that came loose. As Lee said, five minute job dropping the cover and have a look.
Keep a container underneath because there will be some oil in the lower part of the case and remember which case bolt came from where as they are of different lenghts.

[bsa-bill]

Welcome Barry, agree with the comments so far, the vee belts not as positive as a toothed belt, sometimes the cork washer supplied with toothed belt system ( goes behind the large pulley) can be a bit too thick and holds the pulley off the taper, needs cut in half

[Greybeard]

...and remember which case bolt came from where as they are of different lenghts.

I have a special tool to ensure those bolts go back in the right place. It's called 'A piece of cardboard with a rough outline of the case drawn on it and holes punched through with a screw-driver'.
I have the equipment to manufacture these special tools if anyone wants one; only 20UKP each, postage extra.

[RichardL]

...and remember which case bolt came from where as they are of different lenghts.

 'A piece of cardboard with a rough outline of the case drawn on it and holes punched through with a screwdriver.

Same here. Julian S's version is probably milled from stainless steel. (Am I jibing the right master machinist?)

Richard L.

[muskrat]

G'day Barry, another sandgroper. We have a few over there.
Lots of good tips above. That will cost you a proper intro in https://www.a7a10.net/forum/index.php?board=13.0
The dynamo drive sprocket/pulley is on a taper without a key so can slip if the nut comes lose.
Cheers from the other side.

[LJ.]

All genuine and well used. Very hard to find nowadays. 

[duTch]

 

I have a special tool to ensure those bolts go back in the right place. It's called 'A piece of cardboard with a rough outline of the case drawn on it and holes punched through with a screw-driver'.
I have the equipment to manufacture these special tools if anyone wants one; only 20UKP each, postage extra.

 My version is a bit more 'Universal', works for the Chaincase too, and also Gutzzi sump screws, and postage may be cheaper from East coast;

[chaterlea25]

Hi Barry and All,

Barry , glad you made it over from the Britbike forum with your questions

I must have got the upmarket case screw holder, mine is made from a piece of white painted wood 

John

[duTch]

 Hiya NBarry/Baz- I didn't say , so

 What makes you suspect it's slipping ?

[barry2]

Hi Dutch
I "flashed" with a 12 v battery  ( by mistake, should have been 6v ) and it started turning,  sill on bike
Barry