Author Topic: Dynamo drive slipping  (Read 1099 times)

Offline barry2

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Dynamo drive slipping
« on: 24.08. 2018 07:32 »
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
WA

beezermacc

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Re: Dynamo drive slipping
« Reply #1 on: 24.08. 2018 08:18 »
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.

Online Greybeard

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Re: Dynamo drive slipping
« Reply #2 on: 24.08. 2018 09:11 »
 *welcome*

Offline coater87

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Re: Dynamo drive slipping
« Reply #3 on: 24.08. 2018 10:44 »
 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
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Offline duTch

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Re: Dynamo drive slipping
« Reply #4 on: 24.08. 2018 10:56 »

 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... *dunno*
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online morris

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Re: Dynamo drive slipping
« Reply #5 on: 24.08. 2018 11:00 »
 *welcome*

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.
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Online bsa-bill

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Re: Dynamo drive slipping
« Reply #6 on: 24.08. 2018 12:20 »
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
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
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Re: Dynamo drive slipping
« Reply #7 on: 24.08. 2018 12:25 »
...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.

Online RichardL

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Re: Dynamo drive slipping
« Reply #8 on: 24.08. 2018 12:31 »
...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?) *smile*

Richard L.
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Re: Dynamo drive slipping
« Reply #9 on: 24.08. 2018 12:38 »
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.
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Offline LJ.

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Re: Dynamo drive slipping
« Reply #10 on: 24.08. 2018 12:42 »
All genuine and well used. Very hard to find nowadays.  *lol* *yeah*
Ride Safely Lads! LJ.
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Offline duTch

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Re: Dynamo drive slipping
« Reply #11 on: 24.08. 2018 17:44 »

 
Quote
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;
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline chaterlea25

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Re: Dynamo drive slipping
« Reply #12 on: 24.08. 2018 19:39 »
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  *ex*

John
1961 Super Rocket
1963 RGS (ongoing)

Offline duTch

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Re: Dynamo drive slipping
« Reply #13 on: 24.08. 2018 22:11 »

 Hiya NBarry/Baz- I didn't say *welcome*, so *welcome*

 What makes you suspect it's slipping ?
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline barry2

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Re: Dynamo drive slipping
« Reply #14 on: 26.08. 2018 08:10 »
Hi Dutch
I "flashed" with a 12 v battery  ( by mistake, should have been 6v ) and it started turning,  sill on bike
Barry
WA