Festive Greetings from the Shed.
I'm in the process of rebuilding and attending to my early Norton 650ss after it's first few months running after 40 years 'resting'. One of the jobs was to change the sprockets and refurbish the clutch as there was a definite lack of pull over 3000 revs. On stripping I found that the original set up was a 20T on the gearbox and a 19T engine sprocket. I've replaced with a more standard 21T engine sprocket and a 19T on the gearbox. I've also replaced the rather worn and slippery clutch plates as well. Whilst I was at it, I've obtained a new 76 link primary chain from Reynolds via AN.
Otherwise all else as standard and the chain drive was working fine so no belt drive just yet thanks. However I've now hit the buffers and I am actively reconsidering my choices on this.
Everything has fitted back together nicely with no issues, but the primary chain just won't fit and seems to be a least a link too small.
The gearbox is as far forward as possible as well. On checking I've noticed that the aperture in the back of the primary case doesn't move or 'articulate' at all. The gearbox is hard against the casing and can't move any further forward. My efforts to wind the gearbox forward to allow the links to meet just seems to be in vain. I seem to have about 3/4 inch forwards travel left, but how on earth can the gearbox actually move anywhere if the case won't allow this?
In another recent post about primary cases with pictures it was clear that my chain case is bog standard and that there is actually very little back and forward adjustment possible. (Thanks for that Philip Hannam) Before I Dremel the heck out of the case can anyone enlighten me on any of the above? Clearly I am missing something....
Thanks
Kit
Hello Kit - The gearbox…
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Thanks Howard
There is nothing at all like this on my chaincase. See pictures. I've been working the problem and at the moment my maximum movement fore and aft is about 1/16.
The pictures posted earlier don't seem to show this ability. My chain case is otherwise unmolested and seems in good condition. Everything else further forward lines up and the stator holder has engaged properly.
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It looks to me that its been…
It looks to me that its been soft-soldered or silver-soldered into position. There are usually three rivets that hold both elements of the slider and felt gasket into position. You only show the inner chaincase inside element - is there another on the outside of the inner ? If so you should be able to unsolder the sliders fit a felt gasket and river it all together as good as new. If it is just paint stopping it sliding then a scalpel and small hide hammer should be top of your list for Santa. Nil problemo !! Howard
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Another thought Kit - You or…
Another thought Kit - You or a previous owner haven't got an inner primary chaincase intended for a belt primary drive , have you ?? Howard
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Nope. This sat still for…
Nope. This sat still for ages. Not been anywhere a belt drive but there is much mystery about the original bike and it's a bitsa so must not make assumptions
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Has this been over painted?
Ok. Chain case is off again.
Well these are clearly a concentric set of rings. Are we saying that the inner ring should be movable? It looks like it's been painted in place. On the inner face there are four dimples or punch marks. See pics attached
Does anyone have pictures of what this should look like?
Looks like a period of Dremmelling is about to take place to remove the paint. Happy Days!!
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Chaincase
Hi Kit
It just looks to me that when the inner case was powder coated/painted, the movable part was fixed in position by the paint! It can be quite firmly in place, (don't ask me how I know!) cut round the adjustable parts with a Stanley knife (both sides) and when loosened sufficiently a sharp tap with a block of wood and hammer should free it to enable your gearbox to have its full movement.
Regards John O
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Hello Kit - The gearbox mainshaft aperture in the primary chaincase inner cover should be able to move forwards and rearwards about 2.5 inches. So you will need to spend your effort in sorting out that anomaly. Sometimes the rivets that hold both elements of the slider together can get very tight. There is usually a felt gasket between the two elements to stop oil egressing from the chaincase and it can get hard and stiff with standing unused. good luck, Howard