TICK TICK TICK when roll off throttle... GS550 1980

[Guest]

Hi Guys,

Had a look through the forum and cant see an answer to this problem, hope someone can help!

My 1980 GS550 has developed a noise which sounds like its coming from the front of the engine. it happens when i roll off the throttle and the engine slows to between 3k and 2k revs.

The only way to describe it is a click/tick noise between 3 and 4 times. TICK Tick tick tic.. sort of getting quieter as the go.

it doesnt make the noise on idle, and the engine runs pretty sweetly otherwise.

Any ideas? could it be the cam chain? i would post a video but its hard to do as it only happens when off the throttle and moving.

many thanks!

Gadgetboy.

[uk gs nut]

Gadgetboy550, I would check the cam chain tensioner it could be a slack chain. There is tutorials on here, use the search option at the top of the page. Or look here http://www.bwringer.com/gs/camchaintens.html

[Gadgetboy550]

Gadgetboy550, I would check the cam chain tensioner it could be a slack chain. There is tutorials on here, use the search option at the top of the page. Or look here http://www.bwringer.com/gs/camchaintens.html

Thanks uk GS nut,

I had suspected the cam chain tensioner.. but unfortunately it doesnt seem to be the culprit. i unwound the lock nut and checked the setscrew was set correctly at 1/4 to 1/2 turn slack- which it was.

There doesnt seem to be any camchain noise at idle or when the revs are wound on.. the noise only happens when on run down when i close the throttle when moving.

thanks,

gadgetboy

[jsandidge]

Might be your tachometer cable.

[Griffin]

Could possibly be cam walk, which is harmless. It seems to be more prevalent with the two valve per cylinder engines (which yours is) than engines with the four valve per cylinder heads.

My 650E exhibits it if I start it once it's already been warmed up and I blip the throttle.

[chuck hahn]

Exhaust gasket leakage maybe???

[Steve]

Exhaust gasket leakage maybe???

I would suspect exhaust leakage noise more on acceleration, not deceleration.

.

[chuck hahn]

Unless thats the point its sucking in the cold air and making noise.

[Gadgetboy550]

Hi All,

Thanks for the replies. I thought it could have been the speedo drive as it snapped on the way home from a long ride, and sounded like snagging of the broken cable rubbing as i rolled off the throttle and the front forks dived slightly. when i removed the speedo cable it was still making the noise - much to my annoyance!

Tacho cable/drive could be a good call, as it is probabl equally as worn and knackered. maybe i will try removing this and going for a quick test ride, before i spill too much oil!

RE the notes on exhaust leak, it did make a odd noise on low end accelleration in a high gear (3/4 gear at 20mph) when i first refitted the zorst with new gaskets. once i nipped the offending downpipe its all quiet with no leaks.

One final possibility is that its tiny backfires at top of the downpipes.. at lower revs. It seems to be a similar pattern of clicks to the louder backfires at high revs (out of the end can) when the throttle is shut off.. what do you think?


Gadgetboy