ST1100 - 1992 model - Clutch noise

[phrode]

Just bought my used ST1100 and there is something that bothers me. If I start in 1st gear, release the clutch and accellerate slowly, everything is normal.
If I try to be a bit quick, give it a little throttle and release the clutch. There is a terrible sound (like metal on metal).
The clutch is a bit (not sure how to explain in english) too responsive. It is like on and off, and very little in between.

The previous owner told me that there was a small leak in the hydraulic clutch system. Every now and then, he had to refill a bit, but there were no visible leaks he said.

Maybe the clutch is worn out.. Any good ideas?

 

[kiltman]

You may have to rebuild the slave cylinder, and while your at it the master. There are kits for this. Flushing the fluid and making sure the pin hole in the master cylinder wouldn’t hurt either.

 

[SMSW]

How many miles/km on your bike? While clutches can die at any point, the wet ones we have on the ST's seem to last a long long time, and relatively few guys have reported here changing the plates. Rebuilding the slave cylinder, is however a more common maintenance issue. Most clutch/brake issues can be traced to the owner not changing the fluid regularly - many guys do it every year, Honda recommends every two, and the rest of us when parts go south and the bike complains.

As Kiltman said, start with a thorough flush of the system. Suck out the old juice in the master cylinder reservoir, refill w/ fresh and then pump a few reservoirs full of new fluid thru the pipes and slave cylinder. This is often all that is needed. Do the easy things first, there is plenty of time to dig into the bike.

 

[kiltman]

Also replace the brass bushing in the clutch handle, I finally did mine and a world of difference! In my case changing out the bushing made for an easier pull on the handle.

 

[bdalameda]

What you are experience is called clutch chatter. It is caused from running oil with anti-friction additives for automotive use. It can cause glazing of the clutch plates but you may eliminate it by changing to a different oil that is formulated for use in motorcycles with wet clutches (JASO). The sound can be described a a squawking and grabbing as the clutch is being let out and throttle applied. Many times this occurs when the oil is cold but I have seen this also with warm engines. This does not really hurt anything but it can be annoying. If the problem does not go away with an oil change the clutch friction discs may have to be replaced or just live with it.
I have had pretty good success in eliminating this problem using Archoil 9100 additive as it has a very powerful detergent additive that seems to clean up the clutch very well. The Archoil is an anti-friction additive but it works using a borate formula and is compatible with wet clutches, run 1.2 oz. per quart of oil. I am not sure if this product is available in Norway.

Dan

 

[phrode]

Thank you everyone. I will do the hydraulics this weekend @kiltman.. It has done 118000km, and the bike has a full service history @SMSW.
@bdalameda that seems about right. I've had similar problems with my GSX 1981 model, but the noise was not that bad. The Archoil 9100 I have to try... If I cant find it here, I guess I can order it from the US or other countries. But I will start with changing the oil this weekend...

Have a nice weekend

 

[Upt' North]

Phrode,
Clutch noise when you take off like a scalded cat is not that unusual. A few have reported similar noises before.
Good bike oil is a good suggestion but don't be surprised if the noise persists.
I would check the fluid level regularly just in case because maybe it can leak internally at the engine end. It should be easy to bleed through too.
Good luck.
Upt'North.

 

[DaveWooster]

You may have to rebuild the slave cylinder, and while you're at it, the master. There are kits for this. Flushing the fluid and making sure the pin hole in the master cylinder [is not clogged] wouldn’t hurt either.

I am posting merely because I think someone left out a word or two in their post above.

But while I am here, the clutch parts were upgraded before the 1992 model year, right? (1992 is year code N.)

 

[Mariusz Zaleski]

Just bought my used ST1100 and there is something that bothers me. If I start in 1st gear, release the clutch and accellerate slowly, everything is normal.
If I try to be a bit quick, give it a little throttle and release the clutch. There is a terrible sound (like metal on metal).
The clutch is a bit (not sure how to explain in english) too responsive. It is like on and off, and very little in between.

The previous owner told me that there was a small leak in the hydraulic clutch system. Every now and then, he had to refill a bit, but there were no visible leaks he said.

Maybe the clutch is worn out.. Any good ideas?

Hi phrode,
I just bought my 1999 model and have this same issus. When accelerating gently everything is fine but when releasing clutch quickly I hear horrible noise. Something similar to gears grinding and take off is not smooth.

On the top of it I had problem with clutch lever getting soft when temperature raised in slow traffic. Someone suggested to rebuild slave cylinder. I had replaced seals and issue is gone. I also changed engine oil to Motul 10w40 semi synthetic. Clutch lever doesn't get soft anymore and works well. The rattle from clutch basket when engine is cold and grinding sound when taking off quickly persists.

I thought about buying new clutch basket assembly and plates just in case. Used clutch assembly with plates is not expensive (~60GBP on eBay).
This sound is quite worrying and doesn't sound like something that should be there.

Share your findings if you found a solution.

Regards
Mariusz

 

[Larry Fine]

I'm thinking rear hub drive cushions.

 

[ST Gui]

Share your findings if you found a solution.

The post you quoted is from 2019 and the most recents posts from that member that I saw were from 2020.