81 GS450 new noise Cam chain/tensionser or other issue?

[Guest]

Hmm, I've noticed mine tends to get stuck as well when I attempt to manually rotate the knurled knob ccw. Haven't had my motor running yet, so thought it might not be an issue once the motor was running at operating temp. Glad you uncovered the problem, I'll have to keep an eye on it when I get it on the road.

 

[Guest]

If you manage to get a 'pretty' one out of the pair, it's still a good idea to replace the seal on the 'camshaft' as the shaft inherently wobbles a bit and the seals harden up for a leaky combination.

I prefer a Honda seal to the Suzuki one - assuming you can still get the OEM - as it's more flexible and seals better, especially if you've taken the shaft down a bit to get rid of the grooving and such.

It's a Honda ATV part number 91259-VMO-000 [or old bike part 91206-333-003] and should be about $4 - $5. Because it is a higher interference fit on the shaft you will need to chamfer the edge of the shaft a bit to slide it through. It's also a tighter fit in the housing which seals better, plus it's still in production which suggests fresher stock.

 

[jsandidge]

..... The not rotating out explains why it only happened at around 4500rpm and when loaded... tension on the chain was greater and the shaft would not rotate back out any further.

I didn't think they are supposed to rotate out unless done manually.

 

[Guest]

I didn't think they are supposed to rotate out unless done manually.

Maybe by rotating out he meant the plunger moving out of the tensioner. Regardless, having smooth action both ways seems to have fixed it. But I hear you, rotating the knob CCW or 'out' isn't a good idea when it's running. As the Germans say, 'nicht fur gefingerpoken' .

 

[Blue Falcon]

I didn't think they are supposed to rotate out unless done manually.

you are correct, I could not get it past that point, it would lock, it would not move either way from the notch in it.... needed a new one regardless. I could not turn it far enough back to get the plunger all the way down.

 

[Blue Falcon]

Update,

No noise... was the cam chain tension causing the main issue. I had to put 1.5 turns on it... I will be replacing it next week when the other ones come in...will take them apart and see what condition they are in before installing.

 

[Blue Falcon]

Update: Chasing noises. Got "new" tensionsers in, rebuilt them, installed best one, chain noise gone. The plunger spring was gone on my old one, I could easily close it between thumb and forefinger...just lost it umph. Ping sound was loose engine guard mount and motor mount. Now for the latest..

My unknown noise, I think it is a loose clutch basket. Thank you John Park for the post and I double checked everything as the noises were silenced one by one.

1. Only makes noise when rolling, clutch in or out and engine warm.
2. No noise at idle or when stopped regardless of RPM
3. Identified in the "clutch basket" area of engine.
4. Noise is harmonic around the 3500-5000 rpm range
5. Noise comes and goes, I could be doing 40 for 10 minutes and no noise then all of the sudden..noise.
6. When taking dipstick out and checking tightness, clutch basket has very slight play in it.

I am going to order a new gasket and check out the issue. I have one bolt that is stripped I could not swap to SS...I have been looking for a reason to take the cover off to get it off anyway.

On the brightside...apparently this is a common noise in a lot of bikes and does not usually cause issues...other than extreme annoyance.

You mentioned earlier that the sound went away when you pulled in the clutch. Could the nut that holds the clutch on be loose? Usually that's problem only on the big motors, but maybe somebody had it apart and didn't get it done up or there's too much endplay.

Might be able to lever it about through the oil filler. ??

 

[Blue Falcon]

Took out the mechanics ears...stethoscope... before you ask if I know what I am listening for.... I used to do this on jet engines... very distinct sounds... but then again.. I also had a frequency analyzer if I could not "hear" it. Anyway.. no griding, no scraping, NOT coming from cylinders or crank, cam walk - yes ( #1 noise ) , not bearings, coming from clutch basket or area of basket - yes ( #2 noise sounds like hitting an aluminum muffled bell, when I have the dipstick out, the bell sound goes away a little and I am able to localize to the clutch side area...go figure ). Either the basket is loose or something is loose in the basket. My clutch push rod is bent but not bad enough to effect functionality.

Any way about it.... nothing performance wise is affected...is it worth cracking open the sides to take a look. Or should I just live with the noise, can't hear it at 40+ mph lol.

 

[chuck hahn]

Maybe the bent push rod is vibrating enough to be making the sound??? Maybe pull the clutch left side cover and straighten then rod as well as you can and try it again. Doesnt hurt to crack the clutch cover off and ensure bearings are solid and the clutch hub nut is tight too. But that also requires a new gasket..as the rod straightening first doesnt require a gasket.

 

[Blue Falcon]

Maybe the bent push rod is vibrating enough to be making the sound??? Maybe pull the clutch left side cover and straighten then rod as well as you can and try it again. Doesnt hurt to crack the clutch cover off and ensure bearings are solid and the clutch hub nut is tight too. But that also requires a new gasket..as the rod straightening first doesnt require a gasket.

I'm gonna order a new push rod...if I am cracking it open...it's going to be for something.....and also to take out that stripped bolt on the case. I can have the clutch pulled in and it will tink a little bit as I am rolling. I honestly would swear it's the exhaust if I didn't narrow the sound area down.

 

[Guest]

The 80 and maybe 81 had a one piece push rod but the 82 and on were two piece, so you could replace just the outer section if it had an argument with something. I think there was a ball in between the two. ?? The only picture I have handy is of the one piece one. As far as I know, you can replace with a two piece, which is less problematic and I think maybe less prone to leakage as well.

It might even update to a GS500 part which would be easy to source.

 

[Blue Falcon]

The 80 and maybe 81 had a one piece push rod but the 82 and on were two piece, so you could replace just the outer section if it had an argument with something. I think there was a ball in between the two. ?? The only picture I have handy is of the one piece one. As far as I know, you can replace with a two piece, which is less problematic and I think maybe less prone to leakage as well.

yes, I have an 81 450EX, one piece, you can only order a two piece for replacement now, still not that expensive. I don't think the push rod is my issue, but since I found it a little bent, OCD will kick in. Order a push rod, gaskets and call it a fun Saturday.

 

[Blue Falcon]

Found out my analog compression tester needed a bit of calibration. What I get for loaning it out. Digital calibrated compression test was L 127.8 , R 129.1. Not bad for 36+ years and 27k on the engine. gaskets ordered...next friday will be fun... praying for a loose nut.

 

[Blue Falcon]

Guess what I am doing for fun this weekend... Noise... I will find you. Guess I will do the covers and finish the socket cap change out while I am at it, good time to check tolerance on the clutch as well.. give her the covers off once-over.

View attachment 50486

 

[Blue Falcon]

Lessons learned so far....and me with all my experience falling for this

1. Don't trust others gauges.... or your gauges after loaning them to someone.

- My compression gauge was way off, now properly calibrated - had to get a buddy with an electronic gauge to check my cylinder pressure - was not a problem or source of noise
- Friend of mine... student at WyoTech... used his vacuum gauges to set my carbs... smh... "ya they are calibrated" Again, had to use same buddy with digital vacuum gauges to set my carbs....
and when I say calibrated... I don't mean the initial on a cylinder...this thing was so out of whack...I think a spring was toast on one of his gauges. It is nice to know they are pinpoint duplicates of each other now.

2. Have a friend that has all the tools and time to help you - a case of beer and a steak that gets you 30+ years of motorcycle mechanic experience is PRICELESS!!!

3. It never is just "1 thing wrong"...

This was and is a culmination of issues...starting from the day I got the bike. 1 - cylinder missing - was spark plug , 2 - vacuum leak - intake boots and vacuum line to petcock, 3 - carbs keep clogging/bad throttle response/flat spot - had to clean them 3 times.. ultimately it was the disintegration of the petcock sending material in the bowl... caught by the screen. Other issues not found due to gauges not being in tolerance and giving bad readings......

Current status after "tuning" my carbs again today - forgot who said resonant noise to gear box from badly tuned carbs. Mine were not far off, but enough to cause noise... was not the total cure to the noise but added to the problem.

still taking covers off, still have a small rattle bugging me .... and a stripped bolt that has been annoying me for a couple months, hopefully something simple.
cleaning oil pan screen
brushed look on covers and forks - sand/stroke/clearcoat.... I will probably wait on the clear coat.. want to make sure I like the brushed look.

 

[Blue Falcon]

Found the source.... loose clutch basket nut and spring. Was able to spin off the nut with my fingers once I bent the keeper down. Properly torqued now. On another note... One of my spark plugs was broken... went to Autozone to get a couple of new ones.. both of the first two he brought out were cracked and broken on the ceramic... Had to open a new case to get a pair that wasn't. NGK B8ES . Bike is nice and quiet.. well.... as quiet as a sewing machine on steroids can be..

Video of loose nut