Clutch not fully disengaging - any ideas?,

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mel
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Clutch not fully disengaging - any ideas?,

Post by mel »

Bit of background,
Bike is gsxr1000 k7 (track bike) with hydraulic clutch ( there is I believe no adjustment as it self adjusts- so I believe.)

Bike has been stood for quite a while (12 mths) and occasionally started and on optimise in position on stands

Finally got round to thinking about servicing it and giving it a good clean ,however when I went to start it the clutch lever was against the handle bar as if pulled it ,
A quick wipe of ac50 on the pins and levers and new brake fluid( sucked through via a air operated bleeder from the slave valve and all seemed good

Unfortunately whilst the clutch works it does not fully disengage
it was initially running at 13 mph in first on tickover

I stripped the clutch down as whilst the basket was moving I thought the plates may be stuck together this was indeed the case, so soaked the complete clutch in oil overnight and put it all back together after freeing them all apart.

This had limited result as the clutch still dragged but you could here the engine noise change and the mph dropped to 9 mph when pulling clutch in ,you could carefully stop the rear wheel by hand and by slowly using the clutch start the wheel to rotate and stop , but as soon as you let it run too much in gear the clutch would not fully disengage with the wheel back running at 9 mph .

In neutral everything is fine and free, but when using the clutch(bike not running) you can only sometimes put it in 1st pull the clutch in and turn the bike wheel by hand but you can feel the drag

I am assuming I put the clutch plates back correct and changed oil and filter but it shows same problem I had before ( I did not check or touch the push road) which I assume comes from the slave cylinder , to be fair would not know what I would be checking for.

Fairly certain no air in clutch system but have pulled lever back overnight to force any bubbles up to master cylinder if this don’t cure it am sort of out of ideas

If anyone has any feel free to share
Tia
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Re: Clutch not fully disengaging - any ideas?,

Post by Le_Fromage_Grande »

The plates may have swelled, replace the cork plates, you might need to replace the steel plates as well.
My GPZ1100 did this and I had to replace all the plates.
Only other cause will be a hydraulic issue.
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Re: Clutch not fully disengaging - any ideas?,

Post by JackyJoll »

Hoe does it behave when you ride the bike?

If you can stop the rear wheel by hand, that sounds to me like the clutch is not dragging at all.
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Re: Clutch not fully disengaging - any ideas?,

Post by v8-powered »

I know that on the 750 K7 that you can adjust the pack, not sure if same on the 'thou though.....
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Re: Clutch not fully disengaging - any ideas?,

Post by roadster »

If the transmission does disengage but drags enough to prevent neutral being found it could be caused by overfilling the oil possibly combined with high idle speed.
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

Le_Fromage_Grande wrote: Mon Oct 28, 2024 6:28 am The plates may have swelled, replace the cork plates, you might need to replace the steel plates as well.
My GPZ1100 did this and I had to replace all the plates.
Only other cause will be a hydraulic issue.
This is what I was thinking or warped
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

JackyJoll wrote: Mon Oct 28, 2024 7:45 am Hoe does it behave when you ride the bike?

If you can stop the rear wheel by hand, that sounds to me like the clutch is not dragging at all.
Not driven it, it’s on a ramp , to stop the rear wheel you have to run it in gear pull clutch in sometimes the wheel speeds decrease to 9 mph sometimes it doesn’t and by using a glove you can put your hand flat on tyre and let friction slow the tyre to a stop to me I would describe it as clutch disengaging fully rather than dragging
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Re: Clutch not fully disengaging - any ideas?,

Post by Yorick »

I'd take it for a ride to see how it behaves in the real world.
The problem may resolve itself.
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

v8-powered wrote: Mon Oct 28, 2024 8:06 am I know that on the 750 K7 that you can adjust the pack, not sure if same on the 'thou though.....
You can but as it’s the same stack as when it was working I ruled this out
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Re: Clutch not fully disengaging - any ideas?,

Post by v8-powered »

mel wrote: Mon Oct 28, 2024 10:38 am
v8-powered wrote: Mon Oct 28, 2024 8:06 am I know that on the 750 K7 that you can adjust the pack, not sure if same on the 'thou though.....
You can but as it’s the same stack as when it was working I ruled this out
Only dropped this is as on my old K7, it suffered similar after I'd replaced the clutch plates. Adjusted the pack as per the manual and all was good again....
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

roadster wrote: Mon Oct 28, 2024 8:37 am If the transmission does disengage but drags enough to prevent neutral being found it could be caused by overfilling the oil possibly combined with high idle speed.
No problem finding neutral - idle speed is fixed - never ever adjusted it -new oil and filter fitted and is correct - it’s not the gear disengaging it’s the fact the clutch won’t fully disengage
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

Yorick wrote: Mon Oct 28, 2024 10:38 am I'd take it for a ride to see how it behaves in the real world.
The problem may resolve itself.
[/quote
I don’t disagree would certainly make life easier if it did
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

mel wrote: Mon Oct 28, 2024 10:37 am
JackyJoll wrote: Mon Oct 28, 2024 7:45 am Hoe does it behave when you ride the bike?

If you can stop the rear wheel by hand, that sounds to me like the clutch is not dragging at all.
Not driven it, it’s on a ramp , to stop the rear wheel you have to run it in gear pull clutch in sometimes the wheel speeds decrease to 9 mph sometimes it doesn’t and by using a glove you can put your hand flat on tyre and let friction slow the tyre to a stop to me I would describe it as clutch not disengaging fully rather than dragging
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

Le_Fromage_Grande wrote: Mon Oct 28, 2024 6:28 am
Only other cause will be a hydraulic issue.
My knowledge of slave cylinders and the push rod operation is pretty much nil , my thoughts were as the clutch lever on the handlebar had stuck and the clutch plates were stuck , could it be the push rod or whatever is in the slave cylinder being stuck / slightly gunked up stopping the clutch fully engaging - don’t really want to start stripping them all down in case I cause more problems and don’t actually know what to look for as am guessing any movement is in mm
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Re: Clutch not fully disengaging - any ideas?,

Post by Rockburner »

Le_Fromage_Grande wrote: Mon Oct 28, 2024 6:28 am The plates may have swelled, replace the cork plates, you might need to replace the steel plates as well.
My GPZ1100 did this and I had to replace all the plates.
Only other cause will be a hydraulic issue.
cork??
non quod, sed quomodo
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Re: Clutch not fully disengaging - any ideas?,

Post by JackyJoll »

If you can’t get into or out of neutral, with the rear wheel on the ground and the engine running, you might have a dragging clutch.

If you can’t push the bike along the road in gear with engine stopped and clutch lever squeezed back to the handlebar, you might have a dragging clutch.

Keep your bloody hand away from a rotating wheel!
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

JackyJoll wrote: Mon Oct 28, 2024 12:19 pm If you can’t get into or out of neutral, with the rear wheel on the ground and the engine running, you might have a dragging clutch.

If you can’t push the bike along the road in gear with engine stopped and clutch lever squeezed back to the handlebar, you might have a dragging clutch.

Keep your bloody hand away from a rotating wheel!
Top one is fine

Middle one is spot on that was the problem , would also leach and stall if you tried to start it

Bottom one your 100% right even worse when you have to operate clutch with one hand :wtf: at the same time

It was hard to explain in writing but initially on tick over the wheel would rotate with clutch held in and bike in gear the clock would show 13 mph after stripping and freeing the plates this changed and the wheel would do the same thing but down to 8 mph showing on clock you could also hear engine was different when clutch pulled in you had no chance of stopping the wheel at 13 mph but at 8 it was doable once it stopped it stayed stopped as you gently released clutch the wheel would start spinning but once you let it fully out you were back to square 1 with the wheel spinning up to 13 mph

Anyway on the good news side see below
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Re: Clutch not fully disengaging - any ideas?,

Post by mel »

Well how good are all you , :thumbup:
I have been playing with this for over a week

released the tied in clutch lever ( I left overnight)and tried a few times
3,4 ,5 and 6 th gear work perfectly stopping the rear wheel instantly ( had never tried these gears before so may have always been alright

2 nd gear is much better and does stop the wheel in under 5 secs 1st gear takes about 10 but the speed it turns reduces dramatically as soon as clutch pulled in
Am guessing with more torque in 1st and second this would make sense and once I build the bike back up all wheels and callipers are off so I can give a good clean and lubricate I’ll also have a look behind the front sprocket cover and the gear linkage I will attemp it on the ground it’s 95% better I still think that whilst I have fixed the clutch leaver and the friction plates there is a slight resistance in either the slave cylinder or push road but as yorick said I’ll try it in the real world and see if it fully clears

Appreciate all the replies as they either gave me something to try or confirmed something I had checked :clap: :clap:
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Re: Clutch not fully disengaging - any ideas?,

Post by Le_Fromage_Grande »

Rockburner wrote: Mon Oct 28, 2024 11:59 am
Le_Fromage_Grande wrote: Mon Oct 28, 2024 6:28 am The plates may have swelled, replace the cork plates, you might need to replace the steel plates as well.
My GPZ1100 did this and I had to replace all the plates.
Only other cause will be a hydraulic issue.
cork??
You knew what I meant
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Re: Clutch not fully disengaging - any ideas?,

Post by JackyJoll »

There’s plenty cork in my clutch. Big improvement on whatever stupid compound Surflex of Italy stuck on the plates.