Mounting Dynamo into engine plates.

matchbox500 · Post by **matchbox500** » Wed Mar 18, 2009 7:21 pm

I am going to fit the dynamo into the engine plates on my 51 G80 (Dynamo is at the rear of the barrel). There are two screws and a narrow flat plate attached to the dynamo, what do they attach to. Also is the dynamo sprocket just held on with a nut ?.

Cheers
Jim.

volvo850 · Post by **volvo850** » Wed Mar 18, 2009 8:55 pm

Jim
the plate is intended to sit between the engine plates and position the dynamo such that it will be in the correct position (sideways)as regards chain alignment.
Personally I chose not to fit this on my G80, but I did spend some time ensuring that the chain sprockets were aligned.
As regards the sprocket nut, I had to fit a plain washer below my nut to ensure the the groove machined in the nut (for the circlip)
was just outwith the lock plate when fitted over the nut.(ie the circlip was firmly holding the lock plate into the cutouts in the sprocket.Without the washer ( on mine anyway), the groove would have been "below" the surface of the lockplate.

volvo850 · Post by **volvo850** » Wed Mar 18, 2009 8:58 pm

sorry, forgot to sign,
hope above is clear.
good luck
Jim Anderson

Don Madden · Post by **Don Madden** » Thu Mar 19, 2009 1:52 am

As Jim Anderson says, the lock plate & circlip are necessary. Do not substitute locktite, lock nuts or lock washers. There is a drawing in the archives showing the proper setup. Cheers, Don.

laxy · Post by **laxy** » Thu Mar 19, 2009 11:07 pm

the washer under the nut is supposed to be there.Secure sprocket as follows
Place sprocket on armature shaft,making sure woodruf key is in place.
fit washer
fit special nut that has groove machined into it
fit special lock washer over nut
the inner dia. of this washer is serrated and grabs the outside of the nut. the outer edge of the washer has two tabs that turn over and engage in the slots on the sprocket.
a circlip is then fitted into the groove of the nut to hold the locking washer in place.
The tricky bit is tightening the nut enough to hold the sprocket but allowing the tabs on the washer to line up with the grooves in the sprocket.
I use just a touch of loketite on the nut and ALWAYS use new locking washer and circlip.
As far as the locating strip is concerned,if you have one use it.
If for some reason you decide not to then position the dynamo so that the join between the end cap(sprocket end) and dynamo body is in line with the outside edge of the engine plate.
All you have to do now is rotate the dynamo to obtain correct chain tension and tighten the securing band.
A lot of the pins that hold thes bands to the engine plates get bent as a result of overtightening,now might be a good time to take it out and straighten the pin with a big hammer if this is the case with yours.
have fun regards,Keith

56G80S · Post by **56G80S** » Fri Mar 20, 2009 11:00 pm

Not contradicting Laxy, his advice about side to side location should be right, but DO check that the sprocket runs line up properly. These are old machines and it only needs a rogue part and the standard prescription goes wrong.

Many years ago I failed to check this alignment when the non year appropriate AMC box was in. The chains clashed, broke and fortunately it's all now a bad memory. Learn from my mistake, it's a lot cheaper and less painful.

I made up a spacer plate, to a spec. which I think Don provided. If you have one, I'd say use it. If the strap loosens a bit it will stop the dynamo shifting across the frame into the chaincase.

Johnny BEdited by - 56G80S on 20 Mar 2009 11:01:16 PM

Don Madden · Post by **Don Madden** » Sat Mar 21, 2009 1:27 am

The drawing I made is in Christian's Wonderful Archives for all to see. Cheers, Don.

Peter Lecompte · Post by **Peter Lecompte** » Fri Aug 26, 2011 2:36 am

Hi Don,

checked out your drawing on the dynamo locating strip. Same as the one I have just removed from my EAR dynamo. But I am not sure why there is a difference in each end of the strip? And which way does it fit? It obviously does matter... Thanks Peter

RayRST · Post by **RayRST** » Fri Aug 26, 2011 8:54 am

Having has the circlip come off many years ago on my first AJS I always apply Araldite over the clip to ensure it does not come off. I did the same on my present 16M and it has never been a problem. Pushing my bike 5 miles back home from college in the 1960's and most seemed uphill was hard work that I never wanted to repeat, as when the nut and sprocket came off the dynamo chain broke the primary chain.

GOLDSTAR · Post by **GOLDSTAR** » Fri Aug 26, 2011 9:50 am

when I first put my bitsa togethewr the only dynamo I had around was a miller, this of course did not have the metal strip like the lucas one I used it and it was O.K. for a while but eventually it worked its way inro the primary chain case and mashed the contents up a little, the armature was bent also, my advice is to retain the metal strip, elongate the mounting holes if not already thus, and fit it so as to prevent the dynamo moving towards the primary chain, does'nt matter how awkward it is really much better than all the problems omitting it can cause kind regards