Hi Shadow,
I think you are not quite understanding the problem here. The battery is fine. The starter motor good and as far as I can tell all parts of the drive train between the starter motor and the alternator shaft as far as the chain drive are all as they should be.
The noise that I first reported is due entirely to the chain being so slack that it grinds against the crankshaft sprocket (the noise that sounds like gears having their teeth stripped off) as it hangs off the teeth.
In the bikes current state (alternator removed but starting damper and chain still in situ) I can clearly see that the chain tensioner is not providing enough pressure on the guide to tighten the chain enough to grip on the crankshaft. The ratchet is broken so the sprung shaft just slides back and forth without locking as it should. Gravity is playing its part here. The chain is hanging off the bottom of the crank sprocket.
When I put tension on the chain with my fingers and try to turn the damper it is biting on the crank and completing the broken link in the drive train so the only thing that needs fixing is chain tension.
Needless to say my mind has been pretty preoccupied with trying to decide on the best course of action and I have one or two alternatives that I am researching at the moment.
Thanks for your continued encouragement. It really helps to know that I'm not alone with this problem and of course anything that I do will be posted up here for all to see. I just need to find enough time. So busy with work at the moment it's very frustrating.
Despite CBR's comments yesterday, which in the long run are correct, if I can find a way to get this problem resolved without the big strip down it will at least prove one way or another whether the alternator chain has been the cause of the rattle. I think it has. Keep watching this space.....

 

OK. Having done several of these there is no point in attempting to wind a new spring on the tensioner for several reasons. It sounds to me as though the chain itself is stretched beyond its limit. Even without a tensioner it should still not slip but just slap a lot. Also the tension is maintained by the spring & a ratchet pawl which by your description is broken. Where are the bits??? Probably floating around the crank case waiting to be picked up jamming a gear or other part ending in disaster.
Sorry but split the case as there is not a join-able chain available. Replace the tensioner, chain & while you are there do the oil pump chain & even the cam chain. While it's apart it's easy although it does add to the cost considerably.

 

OK, all you sceptics.
I've fixed it and now have a perfect running engine.
When I get home and crack a tinnie open I'll tell you how I did it but I'm not sure you're going to like it. It was not easy.
At the moment I'm riding with the farings off to check for anything that doesn't sound quite right, also because I didn't finish till late last night and couldn't be bothered to put them on this morning before leaving for work.
All I can say is that it sounds as sweet as a new turbine. I feel rather proud of myself.

 

I'd be keen to hear about this !
I thought of fitting a tensioner on the top, but wasn't sure..........
Let us in on the secret !

 

Yep, I'd be interested to hear this one, too..

 

I've just got the photos of the repair uploaded onto my hard drive but have picked up a call to international rescue (my daughter). This will have to wait till tomorrow but I will spill the whole can of beans.
On the way back from work this evening it cruised effortlessly at 110 MPH for over 30 miles. Seems fine so far.
Now to the car for some motorway munching..... wish she didn't have so many bags or I'd go get her on the bike. Damned kids!

 

Ok chaps, I've written this repair up and it's now a PDF at 3.2 Mb. There are photos too. Does anyone know how I can upload this or is it just too big?
Perhaps if any of you really want to dead it I can email it to you.

One of you moderators...... please help! I've spent some time doing this for everyone and don't want to be stopped at the final hurdle.

By the way, she's still running like a champ.