As I haven't pulled my unit apart again yet, I'm not sure if the spring could be stretched a little to give a it of movement to the tensioner, rather than using the metal c- section that Henry has so ably put together.
In addition, I think that a section of high temperature hose may be an idea.
if you were to split it down one side and "wrap it around the spring" it would regain it's original shape ie round, and would completely surround the spring. Using this pipe may also give you a little flexibility in the unit, which the metal doesn't allow, and with it going all the way around the spring it may be more secure. I found some metal straps which may take the heat a little better than the nylon cable ties - worth 4.50 GBP for 10, and they are 8" long...........
Any thought ?

Hi Shadow,

You may be onto something with the HT hose. That's a good idea. The SS cable ties are also a better idea and would definitely give more peace of mind.
The slight give in the hose is also a plus point.
The downside is that wraping something around the spring in that very confined space is going to make the job that much harder but I probably can be done with an extended amount of patience and steady handedness.

I have taken today off work and am about to strip my motor down. The first thing I'm going to do is take off the alternator and see whether my repair has held up or given up. I will send you a pic when I've got it open to help you decide what to do.

Thanks Henry - I wish I'd been able to add more to your original line of thinking, but alas not yet. I will continue with the project, and will be keen to hear from you.
Best of luck with the engine - hope it's not too serious.
Any idea on making changes to the chain through the sump would also be good...

I've found out what's happened!!!!!!!!!!!
Time is not on my side tonight so I'll be brief and give you much more info later and lots of pics but here's the rub.
I took out the alternator shaft having realised already that there was a lot of play in the chain when I took the cover off.
Not only was the repair not there at all but neither was the front of the tensioner casting. It has completely snapped off. I could not believe my eyes.
Having taken the sump off and removed the oil pump I found that the whole shaft of the tensioner had been apparently ripped out of the casting complete. The c section, cable ties and spring were all still in tact exactly as I left it. I found them resting in a rather unsavoury place right between two gears but given that the engine has been turned in every direction this does not give any indication as to exactly where it fell while the engine was still running. It obviously didn't go where it really shouldn't have otherwise it would have been over in an instant. DOn't forget, I managed to ride another couple of miles before finally switching off.
SO.... the conclusion so far. The heat resistant nylon cable ties have held up. The c section didn't come off the shaft. It's the actual casting that's broken.
My guess is that the leverage exerted on the casting by the over extended length of the tensioner shaft is beyond the designed strength limitations of the casting. Although there is no direct leverage exerted by the chain moving over the guide the sheer force of the starter motor driving the chain has shocked the casting as it tried to compress the c section around the shaft and thus broken the casting, the weakest part of the assembly so it would seem.
I've just been trying to see if it's possible to change the tensioner through the sump but I think there's a bolt at the top of the assembly which may be impossible to get out without cracking the cases open. My brain is doing what yours is doing but I do at least have the engine on the bench now without having to worry about whether it's possible or not. Tomorrow it will be possible.
Photos to follow. Time to drink some wine and entertain some friends.
Keep your thoughts coming. You've had a light bulb moment today. Nice one!

OUCH !
Good news and bad, all at once.......
Maybe the c-section needs to be slightly shorter to allow some "flick in the chain" but not enough to allow it to hit the casings.........hmmmmm
Be keen to hear what you have to say after the wine Henry..............

Dam bad luck Henry ... great that it held together , but chit ...breaking the casting :icon_doh: ....
Pics would be real good ...

That wine will om sure ease the pain mate ...

Yep, that sucks Henry....
Kinda mixed feelings, I guess.
I'm glad you found the problem, but busted castings is no good....

Hi guys,
I've been outadaloop for a while after funerals, propping up family and taking a bit of time to dwell on things myself. Haven't felt much like logging in lately but time is on my side again tonight so I thought you'd like to see a couple of picks of the damage.
I still haven't got round to buying my parts yet. All in good time.....
http://i654.photobucket.com/albums/u...g/P1030761.jpg
This is a picture of the Alt chain tensionerveiwed from the underside. See how the boss that contains the ratchet has broken off.

http://i654.photobucket.com/albums/u...g/P1030763.jpg
Here's the bits retreived. Note the cable ties still in tact. I slid them of the shaft/c section and they were tight as hell. There's one mising from the picture by the way. Just a continuity error, it was on there though.

I've got a shed load of other pics on the journey into the engine strip. They'll be in the how to when I finally get round to it.
For now, hope this helps satisfy your curiosity.
I've got too much work on to have time to get this engine back together at the moment. Just need another injection of wages then I'll get back to it.
I'm looking at about £750.00 to throw into this abys. It's lot of dough but I know it will be worth it when she fires up again.
I would say I can't wait, but I'm going to have to...... sigh!

bad luck there henry,any clues to the cause,metal fatigue,been stripped before,milage,a thrashing,service missed,maybe evidence of sealer on joints, its a knock on effect ,one thing slack,then a bang or a rattle,
i hate putting sonething together again without havin it straight in my head,for fear of it being short lived.

something that maybe is stickling ya to saying ,,,WHY?

The why is simple in my opinion.
Sudden stress from re-starting or perhaps stalling the engine.
Too much stress on the over stretched tensioner shaft. The angle of the shaft against the chain guide is not 90 degrees so it seems to me that it had too much force applied to it which forced the shaft against the weakest point of the assembly. The casting was exposed to a greater force than anticipated by design.
Do you think I'm right? It could be that I've just suffered random metal fatigue.
What really annoys me is that Honda in all their cleverness in designing this engine did not build in ease of maintenance for the largest chain in the engine.
I seriously believe that most people's woes about cam chains are not at all well founded. It's this deeply buried component that has more to do with Honda rattles. Now I'm about to spend as much as I paid for the whole bike just in the engine. Ho ho..... he he...... lock me away until the daffodils come out.