'82 GS450 Engine Chatter - Cam Related?

**roeme** · 02-23-2021, 05:19 AM

Form the described symptoms, it's almost sure that the tach gear (both on cam and the gear itself), tach cable or combination thereof must be the culprit.

Remove valve cover, inspect thoroughly, take pictures and put them into this thread.

Also note that any of the parts number 19 to 22 on the respective parts fiche are suspect (hotlinking picture from https://www.cmsnl.com/suzuki-gs450e-...list/FIG3.html, not sure if it works):

**VGplay** · 02-23-2021, 12:24 PM

Something with the tach gear makes sense but when I disassembled it nothing looked scored or gave an indication of something being off. It came apart no problem (once I pried loose #20 on the fiche from the head, that was pretty stubborn) and everything fit back together without a fight. I should mention that I did replace the oil seal while looking at it. I didn't get pictures of everything while it was apart, but here is the gear removed.

I probably should've waited another week or so to post this thread, won't have time to take the valve cover off until maybe next weekend. Thanks for the thoughts, I'll update this thread with some pictures of the cover removed when I have a chance.

**Guest** · 02-23-2021, 07:38 PM

The cam gear is softer than the driven gear. If you try to install the exhaust cam with the tach drive installed, the cam gear can get munched if it doesn't mesh right. Make sure the engine gets turned two revolutions and examine the full cam gear as it goes by.

If this is the problem then you don't have any options but to replace the cam. I know it happens because I've been a victim of my own carelessness in this regard. If the problem was the cable itself I'd think it would be broken by now.

**roeme** · 03-10-2021, 09:41 AM

Originally posted by John Park

(...)

If this is the problem then you don't have any options but to replace the cam. (...)

Well, one option would be to temporarily forego RPM indication and plug the hole.

**Gorminrider** · 03-10-2021, 11:42 AM

haha! ^^Yes. Tachometers aren't awfully useful anyways unless perhaps you're deaf. Speedos-you need. Tachs you don't.

But that gear looks ok. What I don't get is your timing chain "going crazy"..

and then it started a very loud and tactile ticking when running. Definitely sounds like it is coming from the head/cams and it causes the cam chain tensioner to go crazy.

I don't see an indication that your tach caused it and I am seriously wondering where the tensioner is "at" after viewing the 1st video. It is NOT supposed to do that.

**roeme** · 03-11-2021, 05:32 PM

Originally posted by Gorminrider

haha! ^^Yes. Tachometers aren't awfully useful anyways unless perhaps you're deaf. Speedos-you need. Tachs you don't.

But that gear looks ok. What I don't get is your timing chain "going crazy".. I don't see an indication that your tach caused it and I am seriously wondering where the tensioner is "at" after viewing the 1st video. It is NOT supposed to do that.

Hmmm, you think by wiggling the cable he artificially tensioned the timing chain, and then the whole system went into just the right resonance equilibrium? Or that was just the right amount of resistance to whack the tensioner back into proper operation?

Hmmm. I'd first try to conclusively rule out the tach gear. Note that the tach gear picture is from _before_ he put the engine back together.

**Grimly** · 03-11-2021, 09:10 PM

Originally posted by roeme

Hmmm, you think by wiggling the cable he artificially tensioned the timing chain, and then the whole system went into just the right resonance equilibrium? Or that was just the right amount of resistance to whack the tensioner back into proper operation?

It sounds crazy, but I think you might just have something there.

**Gorminrider** · 03-12-2021, 12:21 PM

Originally posted by roeme

Hmmm, you think by wiggling the cable he artificially tensioned the timing chain, and then the whole system went into just the right resonance equilibrium? Or that was just the right amount of resistance to whack the tensioner back into proper operation?

Hmmm. I'd first try to conclusively rule out the tach gear. Note that the tach gear picture is from _before_ he put the engine back together.

Did you see the video?

**roeme** · 03-14-2021, 06:47 AM

Originally posted by Gorminrider

Did you see the video?

Yes, what about it? It's exactly why I'm a bit stumped that by merely wiggling the tach cable the issue (apparently) went away.

But also, this could've been sheer coincidence, forgot to take this into account.

**Gorminrider** · 03-14-2021, 10:04 AM

I'm thinking the tensioner is a bigger problem than peculiarities of the tach. I couldn't see much of anything about anything in the second video..I hate these anyways. People spend 30 seconds starting the bike and then jerk the camera all around at various places for a few seconds after. What's so "obvious" and plain to them is never so to me.

**GregT** · 03-15-2021, 01:38 AM

I'd pick it's a tensioner problem. The twins have uneven pulls on the camchain and any slack is readily heard.
If the tensioner isn't locking but bouncing in and out you'd get a lot of noise.

Wobbling the tacho cable around shouldn't affect anything.

I'd set the tension as per the manual - then do what's not in the manual and lock it via the screw on the side and tighten the locknut too.
If this gets rid of the noise you've proved it's the tensioner.

FWIW, on GS's with the stock tensioner which are going to see the track or hard use, I lock the tensioner every time.

**Gorminrider** · 03-15-2021, 10:22 AM

If the tensioner isn't locking but bouncing in and out...

Yes, that's what it does in the video. Somebody might have taken it apart and reassembled wrong..?

**VGplay** · 03-24-2021, 11:22 PM

Next weekend... one month, what's the difference?

That was some really impressive detective work guys. Yes I did rebuild the tensioner using bwringer's guide. After reassembly the mechanism seemed to work as intended but the bike needed more work before I could ride enough to uncover this problem.

Originally posted by GregT

I'd set the tension as per the manual - then do what's not in the manual and lock it via the screw on the side and tighten the locknut too.
If this gets rid of the noise you've proved it's the tensioner.

FWIW, on GS's with the stock tensioner which are going to see the track or hard use, I lock the tensioner every time.

I removed the tensioner, reset it, and remounted it. I will admit when I first rebuilt it I did not do the step in the manual where you slightly turn the crank backwards before turning it correctly to set the tension. That certainly could've played a role. I also did as GregT recommends and tightened the lock screw after setting the tension.

And the chatter is gone! Took the bike around the block up to 55 and the engine is smooth. I think I'm a little lucky the chain didn't skip any teeth if it were flailing inside the engine, everything felt normal and in time.

What would the next step be? Just loosen the lock screw and see if it goes back to chattering? Is it advisable to ride the bike with the tensioner locked? In that case would I loosen the lock screw if I notice any change in cam noise? While I had the tensioner off I really worked it and didn't find any play that would explain the bouncing it was exhibiting, it let spring tension out and wouldn't push in without turning the knob.

I'm seriously impressed. Thank you all for your advice!

**free99** · 03-25-2021, 01:34 AM

Watching this thread, as I had an odd & similar issue with my tensioner until I kind of forced the knob clockwise.. Hadn't thought to lock it though.

GregT, when you do keep it locked, what are the constraints? I imagine you have to do that only after the engine is fully warmed up, as well as re-locked after every x miles?

'82 GS450 Engine Chatter - Cam Related?

'82 GS450 Engine Chatter - Cam Related?

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