Clutch slip! Please help!

[Addy Leung]

It has aftermarket springs, stronger than the stock springs.
New clutch plate (aftermarket cork one but not a Barnett kelver one.). I put it oil for a week before I install it.
It has good metal plate, like new, with no burn marks. New clutch cable.
Checked the clutch hub cover also, no problem.
Just change oil recently, not more than 500miles.

When the engine speed more than 4000rpm, it start slip. Under 4000rpm, it is still ok on all gears.
I need to set the clutch lever has some tension than I can shift the gear easily.
If I set the clutch lever with 2mm free play, I can not change the gear and also, it is still slip.

I did change the clutch engine cover but no improvement.

My next step will change a set of new barnett kelver and also change the two small bearings on the shaft of the engine clutch cover.
Do anyone have any suggestion!!!!!

Bike is GS1100 base with GS1150 head and 1166 big bore kit and mild cams, GS1150 stock carbs with kerker 4-2 exhaust. The engine torque is good. The old clutch plate was a set suzuki stock one and the engine did not slip when I just got the bike 1.5 year before.

[chef1366]

I had a similar setup and had to get Barnett HD clutch springs. Never slipped after that.
If it still slips get FBG or stock Zook fibers.

[SqDancerLynn1]

For the 1100/1150 their are different clutch setups. Did you get the right number of disks, they are a different thickness..

[Addy Leung]

The clutch basket and crank are from 1100.
I see there is a metal plate lock by a piano wire on the inner hub.
there is total of 9 friction plates and also 9 metal plates ( inculding the locked one at the base).

I think there are two seperate problems.

1/ clutch slip - may be because of the quality of clutch plates.

2/ shifting gear problem - I need to pre-set some tension on the clutch wire. If I let it have some free play ( 2mm) on the clutch lever as mentioned by manual, I can not shift the gear even the lever pulled all the way down. But it is also a problem if I set the clutch wire with some tension, that means the whole clutch set is not fully pressed together.

[gert du prez]

I have to agree with SqDancerLynn...

I even ordered the original clutch plates (friction and metal disks) for my GS1100 a year ago (or so) and after installing had a slipping clutch (above appr. 3,000 revs).

Lucky for me, a friend had the same issue before on another brand than Suz (why would you buy that, ok, that is not the discussion here) ...

to measure is to know...the thickness of the metal plates was different (smaller), so I had to reuse some of the old plates...

had no problems with the clutch since then...(15,000 km later)

[salty_monk]

Check service limits (thickness) of metal plates & also check the thickness of the fibres. A fraction of a mm x 18 plates can make a lot of difference!!

If all you've done is change the fibres I would guess that the new fibres are not thick enough compared to the old ones.

Dan

[Baatfam]

Motorcycle oil, correct? Not car oil with friction modifiers?

Just checking....

[Rudeman]

It has aftermarket springs, stronger than the stock springs.
New clutch plate (aftermarket cork one but not a Barnett kelver one.). I put it oil for a week before I install it.
It has good metal plate, like new, with no burn marks. New clutch cable.
Checked the clutch hub cover also, no problem.
Just change oil recently, not more than 500miles.

When the engine speed more than 4000rpm, it start slip. Under 4000rpm, it is still ok on all gears.
I need to set the clutch lever has some tension than I can shift the gear easily.
If I set the clutch lever with 2mm free play, I can not change the gear and also, it is still slip.

I did change the clutch engine cover but no improvement.

My next step will change a set of new barnett kelver and also change the two small bearings on the shaft of the engine clutch cover.
Do anyone have any suggestion!!!!!

Bike is GS1100 base with GS1150 head and 1166 big bore kit and mild cams, GS1150 stock carbs with kerker 4-2 exhaust. The engine torque is good. The old clutch plate was a set suzuki stock one and the engine did not slip when I just got the bike 1.5 year before.

Get some stock friction plates and use aftermarket (Barnett) springs. Are you using the correct bellcrank? I ask because it looks like you're mixing parts between 1100 and 1150. I'm not at all familiar with the 1150 so I would not mix clutch parts.

Also want to be sure you have proper free play set otherwise in addition to your current problem with slippage you will cause accelerated wear on the throwout bearing.

The point about the oil is a good one. Also back in the day whe these bikes were relatively new. We never soaked our fiber plates in oil. We coated them with fresh engine oil, buttoned it all back up and let the engine and oil warm up thoroughly before taking it for an ops check. Never had a problem.

[Mysuzyq]

Motorcycle oil, correct? Not car oil with friction modifiers? ..

New clutch plate (aftermarket cork one but not a Barnett kelver one.). I put it oil for a week before I install it.
Just change oil recently, not more than 500miles. ...

Baatfam asks a good question....is it the same type of oil that was used earlier, when the bike ran well? I found slight slippage happening in a 'quick downshift combined with WOT' situation when using my synthetic blend (Amsoil) mixed with Castrol GTX in A 1:3 ratio. I bought new OEM springs to install, but simply changing to full-conventional oil took away the slip.

Tony.

[Addy Leung]

FYI and update.

I changed the oil to conventional oil but the two problem still there - 1/ still slip, 2/ and hard to shift and no free play on clutch lever.

Then I replaced friction plates to a barnett kelver one. Now I can set the free play on clutch lever and the shift is much more easy.
The slip is improved but still a little bit, especially on 2nd gear after 4000rpm.

I think the shift problem is due to the edge of the non-barnett new plates is sharp and is not easy to move forward and back inside the basket when you pulled the clutch lever. So that it is always engaged the gear and make it hard to shift. Since the barnnet one is made of aluminum, it is more soft and smooth.

I think the slip will be take over after a month time when the barnett one are fully run in .
Is I think it right?

[bonanzadave]

had to get Barnett HD clutch springs.

I would try 3 Barnett springs at least now that you have Barnett fibers. I ran a Barnett pack with stock springs and spun the fiber right off the discs.