Opinions please

[Mumu]

Regarding my ongoing saga with a knocking sound when warmed at idle (99% certain it's the cam chain hitting the top cover), I went to see the local bike mechanic this afternoon.
He reckoned that by 25 - 30k miles the cam chain used on a GS500 is pretty much done for and no matter how much it is tensioned it will still ride up after the back sprocket and hit the top  cover.  As such in his opinion I should strip the engine down and fit a new chain / guide blades etc, however given my extreme reluctance to do this (DEFINITELY not paying someone else to do it and I don't really have the time) I could try turning the tensioner up a notch manually.

What are peoples opinions on this, should a cam chain last longer than 26K miles, is it wise to turn the tension up manually, would it then be over tensioned when cold??
What are the chances of jumping a tooth or two if I leave it (although it sounds too embarrasing when pulling up at lights to leave it as it is)??

Sorry for all the questions, but until I get my bike running ok I can't post about how much fun my GS is  

[Pkaaso]

Welcome to the board Mumu.


I need some advice here too!

I'm starting to have the same problem.  It was just when the bike was cold but now it seems to be staying longer.  

I'm still learning a lot about this engine but, from what I understand - The cam chain tensioner should (if working properly) take up all the play and not allow the chain to be TOO loose.

I'm going to check my tensioner in the morning (Sunday), and see if the spring feels right.  I will also give it a MANUAL "click"  tighter to see if this helps anything.

Except for replacing the tensioner, I can't think of anything else.  The cam chain (unless you beat the crap out of it) should last longer than that.  I"ve got 42,000 on this botom end/chain/tensioner.

In the manual, there is a mesurment to take from one link pin to another (I have to look for the number and the distance). I think you can take this mesurement with the valve cover off and without loosing the chain.
If it's too much, the chain should be replace.

Otherwise, I can only guess the tensioner is wearing out and needs replacing.

Anyone have any advice???

Paul

[gsJack]

......local bike mechanic......reckoned that by 25 - 30k miles the cam chain used on a GS500 is pretty much done for and no matter how much it is tensioned it will still ride up after the back sprocket and hit the top  cover......should a cam chain last longer than 26K miles.....  

I have 77,500 miles on my 97 GS and the cam chain is still in proper adjustment.  I did the valves recently and there is no marking inside the valve cover.  I had "the noise" shortly after I bought the bike new.  Only when hot and only at idle.  A knocking noise in the top of the engine. I'm pretty much convinced it"s a camshart shucking back and forth.  One of the camshafts has sideplay and the other doesn't.  When I changed from 10W-40 dino juice to 15W-50 Mobil 1 synth at about 5k miles the noise went away for 50k miles.  It then came back, but went away again at 70k miles after I changed to the 15W-40 dino juice truck oil.  Only heard it a couple times after that.  The noise is affected by oil viscosity.  

My newer 02 GS does not have "the noise" although it had 4400 miles on it when I got it.  Now has another 1k miles and no noise.  Since the bike was serviced by the stealer before I bough it and had a fresh oil change, I am not sure what is in it.  I will be changing the oil soon and checking the valves.  I will be looking for camshaft sideplay and/or the lack of it. Maybe I'll manage to convince myself completely about "the noise" with the 2 bikes.  I'm only about 99% sure now.   :lol:  :lol:   I'll be using the Delvac 1300 15W-40 truck oil in it also.

Having said all that, it's quite possible your noise isn't the same as my noise and is caused by something else.

I forgot to answer a question about oil from Rashad recently so I'll say it here.  I'm gonna skip the Mobil 1 with this bike since it's not the true synthetic it used to be and go with the Mobil Delvac or Shell Rotella 15W-40 dino juice truck oils for now.  It's a lot less expensive and possibly just as good.  Time will tell.  

[Mumu]

Hi gsJack, its nice to know that a GS can survive that many miles with some TLC.  I think mine was somewhat abused by the previous owner, but I will get her running right again.
I checked my cam shafts also this afternoon, and the intake does indeed have approx 0.4mm end float and pushing it back and forth by hand did make a kinda familiar sound.  Hmmmmmmmm got me thinking this could be the culprit too  
Still at a loss as to why cam shaft end float would produce such a regular but not continuous noise, as I said in a previous post: clunk,clunk,clunk,clunk..............clunk,clunk,clunk,clunk...........clunk,clunk,clunk,clunk...........  ad infinitum
But only at 1200 - 2500 RPM and only when fully warmed i.e. after at least 15 minutes riding.
Oh well, guess I will just have to ride it and see how it goes.  Now if only I could get that damn oil drain plug out...... (sourced a replacement oil pan from a breakers today - will just swap the whole lot out)

And Hi to Pkaaso too.  One thing I will say after playing with my tensioner today is be careful how much you turn that screw to increase the tension.  The plunger moves a surprising distance per turn, I would guess no more than 1/4 turn would be a good start if you decide to try this.  Can always reset it, but I think the consequences of running a cam chain too tight will not be good.

[Pkaaso]

Hmm, good point.  I will watch that.  I think I will change out the tensioner with one out of a 99' (low milage) motor I have and see how it changes the noise.

Thanks all,
Paul

[Sportbilly]

clunk,clunk,clunk,clunk..............clunk,clunk,clunk,clunk...........clunk,clunk,clunk,clunk...........  ad infinitum
But only at 1200 - 2500 RPM and only when fully warmed

My '89 has done this for about 35000 miles.  No problem yet.  A greasy monkey told me once that it was cam end float, not to worry about it, so I didn't.   :mrgreen:

And it sounds *exactly* how you describe it.

[Ed89]

Mine does it as well.  89 with 27000 miles (or so).  Thanks for the pointer!  I never did figure it out myself.

One more data point: I notice that when I start the bike in the morning, I hear about two clunk-clunk.  Then it is OK (until the second traffic light when I have to idle with the engine already warm).


Cheers,
e.