Gs1000 engine rattle: cam chain or clutch?

[AndyC]

Hi all!

My motor has developed a light rattle audible on the overrun and under load. I thought it maybe loose bodywork, however deffo sounds like it's coming from the engine.

The carbs have been tuned and balanced, and apart from this noise, the bike runs beautifully.

Opinions welcome!

Thanks

https://youtu.be/pldmMQfqr7k

 

[steve murdoch]

I did not hear much on your clip.
Any chance you could do another clip and leave out the revving.
A light, rhythmic ticking/rattle from the top end could be "cam walk" which is not a big deal.
An example...... https://www.youtube.com/watch?v=GZtAZZVCpxs

 

[AndyC]

She is indeed a "walker", but this noise only happens on the overrun, or under load. In the clips, you hear the "vroom" as the revs increase, then a kind of "paaahhh" as the rattle kicks in as the throttle is closed.

I'll take another vid and load it up shortly - thanks for your feedback Steve!

 

[AndyC]

Here's a bit more:

The rattle at around 3000 rpm: https://youtu.be/w8hzui-vODI at 28 seconds you can here the "buzz" really clearly.

The rattle under load. Sorry, hated doing this video, felt like I was kicking a puppy: https://youtu.be/5NCNibeJpAU 13 secs, 28 secs and 33 secs.

Sounds Clutch/gearboxy?

AC

 

[steve murdoch]

In the second clip the racket at 28 and 33 seconds sounds like a clutch rattle.

 

[AndyC]

Cool - thanks, I'll pull the cover and take a look. Thanks!

 

[Brendan W]

Before pulling it, open the oil filler and see if the clutch is visible. Put the bike in gear and reverse the load on the clutch by rocking back and forth.
If I'm not mistaken the main drive is helical and if the clutch is loose it should pull in and out a bit.
Mine was so bad the oil pump lost drive on the overrun and the pressure light came on.

 

[steve murdoch]

As Brendan mentioned, start it and open the oil filler.
Might be sacked springs rattling around.
https://www.youtube.com/watch?v=_Mh7AzXLOnU

 

[chuck hahn]

Grab the tentioner with pliers and give a little counter clockwise twist to ensure its not stuck.

 

[AndyC]

Thanks for all the responses!

OK - so. Reset cam chain tensioner, no issues that I coukd see there.

Popped the bike in gear, and rolled it back and forth. No movement in clutch.

So have removed clutch core and basket. A fair bit of lateral play in the basket, so I think the needle bearing may be a little tired.

One thing I did notice was that the clutch plates were looking pretty dry. How much oil should be getting into the clutch core and plates?

 

[Brendan W]

One thing I did notice was that the clutch plates were looking pretty dry. How much oil should be getting into the clutch core and plates?

Quite a bit. With the motor running the clutch could throw oil out the filler opening.
When the springs load up the plates it will squeeze the oil out and the surface appear dry, sort of.
Wouldn't be much of a clutch otherwise

 

[AndyC]

That's a fair point. The clutch was actually working fine, so I'm guessing there's enough oil getting in there.

What are the symptoms of the clutch needle bearings wearing? And also, what is the significance of the tiny "cushion" part i see in the exploded parts diagrams for the gs1000e clutch?

 

[chuck hahn]

3 bolts hold the starter clutch to the back of the rotor and if they come loose they chatter. AND the vibrations travel down the crank and throughout the cases so i would check this also

 

[AndyC]

Good shout - I will investigate today.

 

[AndyC]

https://youtu.be/QDDeW9VvdaI

Yep, the starter clutch appears to be loose - heaps of play there. Can I access those bolts without pulling the rotor?

 

[chuck hahn]

Pull rotor and use new grade 8 bolts with a drop of red loctite on them

 

[AndyC]

Pull rotor and use new grade 8 bolts with a drop of red loctite on them

OK - Rotor pulled. New starter clutch installed, and all rebuilt.

Tada! No more noise. Thanks all!!!!