Can anyone help? I have a noise that starts rattling about 3500rpm up to 6k, (very metallic noise) plus is still noisy under load.
I have read numerous information about rattles in this area and one being the output shaft rivets, mine has the 12 rivet version so ruling that one out plus alternator monkey nuts are all good.

Things that have been done:
                  Alternator bearings
                  Monkey nuts checked
                  New clutch plate
                  Timing chain and all tensioners

To be done but I can't believe are related:
                  Ignition timing.
                  Throttle body balance.


    Question is:  1) Where is this type of noise coming from in the intermediate section of the engine? 
                       2) Could the casing be worn that holds the gears?
                       3) Which gears are prone to this problem if any?
                       4) Could it be something else?

Does it go when you pull the clutch lever in? If so it could be that the wire ring behind the clutch diaphragm spring was not lubricated when the clutch was done.

Rather delayed reply:
Thanks for your reply RicK G. The noise doesn't go when the clutch is pulled in, Using the basic method of screwdriver against the ear, its sounds noisiest at the back of the alternator, I did double check the other day the monkey nuts, as they call them, in the alternator drive, some time ago, I had changed the bearings as-well.

I feel that I have nothing else but take a look at the sprag/one way clutch gear which is just inside the intermediate housing connected to the alternator drive, (according to how I'm looking at the diagram on Real oem) would you agree?

What is "checking" the monkey nuts? You might want to try replacing them.  They don't cost an arm and a leg.

duck wrote: They don't cost an arm and a leg.

They just cost a few nuts.

I would be replacing the nutz. Even if they look OK they can be noisy when they are old and hard, they should be rubbery and soft like the rubber compound on a soft tyre.

Ok will do, Thanks guys, will keep you informed.

I have changed the nuts on the alternator drive, but still sounds very noisy, plus testing with a screwdriver on the back of the alternator I can feel lots of noise resonating through.

Going out for a ride tomorrow will have a closer look/listen. 

I did read this which I guess is very feasible?
http://k-bike-knowledge.000webhostapp.com/k100-Renovation/K100.htm  

As a 1992 model with a 12 rivet output shaft is it possible that the Torsion spring on the output shaft to be rattling, or are they an improved quality on later models?

Thanks in advance for any suggestions.

I don't know what others think of this idea but one way to eliminate the alternator as a cause would be to remove it and run the bike without it to see if it still makes noise.

As long as you have a good battery you can start and run the bike without the alternator and just run it off of battery power for at least a few minutes. (Or you could jump it to a running car and run it longer.)

That's what I'd do just to be sure before tearing into the engine.

duck wrote:I don't know what others think of this idea but one way to eliminate the alternator as a cause would be to remove it and run the bike without it to see if it still makes noise.

As long as you have a good battery you can start and run the bike without the alternator and just run it off of battery power for at least a few minutes. (Or you could jump it to a running car and run it longer.)

That's what I'd do just to be sure before tearing into the engine.

i once did that ,by accident i forgot to plug in the alternator after a change of nuts😳,it ran just fine for about 30km
only after parking the bike in my garage did i find out that i did the hole trip on battery power 😬

k-rider