More ideas, on My thread Byron mentioned: Sounds like there is moisture in the fluid and when it gets hot it vaporizes and you begin to feel the clutch slip. A complete fluid change, using a good high heat brake fluid should resolve the issue. I had a similar problem with a car and actually had to go with a synthetic fluid to keep it from boiling.
Clutch biting when hot
- Thread starter acaffair
- Start date
Changed the clutch hose - tried three types of motorcycle semi synthetic oil, clutch fluid dot 4- changed many times trying to solve problem. Ready to give up.
ST1100Y
Site Supporter
Do clutch basket or centre-hub show any wear/ripples from the friction plates and/or the lining-carriers?
Orientation of the steel plates correct? (their punched-edges)
Orientation of the steel plates correct? (their punched-edges)
I have changed the clutch basket and centre hub - same problem. The most significant positive change was the metal clutch discs but
not a cure. All are fitted with the smooth edges facing the engine.
Going to pull engine over the winter and change the clutch damper shaft -- the only party i have not messed with????? But why when HOT!! beats the hell out of me
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ST1100Y
Site Supporter
Even while not totally "impossible" I'd be amazed if the damper/safety-coupling in the primary shaft has failed... that thing is pretty rugged...
I've seen a prop-shaft damper/coupling having worn to some clearance though... this sounds a significant "knack" or "ding!" upon take-offs...
I've seen a prop-shaft damper/coupling having worn to some clearance though... this sounds a significant "knack" or "ding!" upon take-offs...
I have just finished changing the prop shaft.
I'm the same as you? Can't be the damper shaft but I have changed everything except the damper shaft. Just what throws me is it is perfect when cold and after a few miles back comes the biting of the cushy rubbers when taking off from stationery. It is ok when starting off going down hill but back it comes when the load is increased from a hill start. It would seem logical that if the damper was faulty then it would not take up the drive smoothly. Anyway winter is around the corner so out will come the engine and will change the damper shaft. If still the same the st11100 will go in the bin.
ST1100Y
Site Supporter
One other "simple" thing to check/replace before going overboard in knocking the engine apart:
How old are clutch lever, brass-bushing and the small push-rod actuating the master cylinder?
The brass-eye on the clutch lever does wear down, gets oval, causing uneven movement of the lever/kinematic
Same on the brass bush and that push-rod...
*maybe* the wear has gone so far it alters movement/actuation of them parts, so while you are gently releasing the clutch-lever, the kinematic actually lets the master cylinder *pop* out on the last few mm, causing the clutch to *bang* shut, thus the drive-line "hammers" into the hub dampers...
And the reason this happens only/mostly with a warm engine, is the minimal thermal expansion of brake-fluid and other components of clutch hydraulic, push-rod of slave cylinder, releaser, etc... as additional "variable" in the tolerances of the moving parts/assembly...
The actual movement down there in the clutch from "open" to "engage/close" is really minimal (probably < 1mm), so the actuation by lever, kinematic and master cylinder has to work precise and smooth...
I frequently need to replace brake- & clutch lever plus the other small items due to wear of the pivot bearing, and I'm also keen on maintaining those parts by cleaning and packing marine grease into all moving and contact parts.
The parts in question (clutch master) would be:
22884-MB0-006 ROD, PUSH
22885-MB0-006 BUSH
53178-KE8-006 LEVER, L.HANDLE
90114-MA5-671 BOLT, HNDL PIVOT (maybe)
45504-410-003 BOOT COMP. (the small rubber boot protecting push-rod and master cylinder; often neglected)
While at it the same on the brake master:
53170-MZ1-831 LEVER ASSY, R HA
90114-MA5-671 BOLT,HNDL PIVOT (maybe)
45504-410-003 BOOT COMP. (same as on clutch side)
Worth a try looking at those and if found faulty/worn won't cost an arm and a leg to replace.
How old are clutch lever, brass-bushing and the small push-rod actuating the master cylinder?
The brass-eye on the clutch lever does wear down, gets oval, causing uneven movement of the lever/kinematic
Same on the brass bush and that push-rod...
*maybe* the wear has gone so far it alters movement/actuation of them parts, so while you are gently releasing the clutch-lever, the kinematic actually lets the master cylinder *pop* out on the last few mm, causing the clutch to *bang* shut, thus the drive-line "hammers" into the hub dampers...
And the reason this happens only/mostly with a warm engine, is the minimal thermal expansion of brake-fluid and other components of clutch hydraulic, push-rod of slave cylinder, releaser, etc... as additional "variable" in the tolerances of the moving parts/assembly...
The actual movement down there in the clutch from "open" to "engage/close" is really minimal (probably < 1mm), so the actuation by lever, kinematic and master cylinder has to work precise and smooth...
I frequently need to replace brake- & clutch lever plus the other small items due to wear of the pivot bearing, and I'm also keen on maintaining those parts by cleaning and packing marine grease into all moving and contact parts.
The parts in question (clutch master) would be:
22884-MB0-006 ROD, PUSH
22885-MB0-006 BUSH
53178-KE8-006 LEVER, L.HANDLE
90114-MA5-671 BOLT, HNDL PIVOT (maybe)
45504-410-003 BOOT COMP. (the small rubber boot protecting push-rod and master cylinder; often neglected)
While at it the same on the brake master:
53170-MZ1-831 LEVER ASSY, R HA
90114-MA5-671 BOLT,HNDL PIVOT (maybe)
45504-410-003 BOOT COMP. (same as on clutch side)
Worth a try looking at those and if found faulty/worn won't cost an arm and a leg to replace.
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Have changed the master cylinder, fitted a new repair kit. Changed clutch lever and brass bushing came with master cylinder. (Changed out the complete handlebar assembly)
, did the same with the slave cylinder fitted a new repair kit, then replaced the slave cylinder again. Changed the hose also?? Don't know how many times i have changed the clutch fluid.
When taking off you really have to be so easy on releasing the clutch, having to close the throttle when moving then fully releasing the clutch, not very handy with cars climbing all over my back end. BUT when cold! smooth as you could wish for. If was there all the time i would have said yes the Damper but i not sure. Anyway a big job ahead of me to eliminate the the Damper from my investigations.
The only thing is the metal clutch plates i have them installed with the smooth edges facing inwards toward the engine? is this correct??
I have a new fjr1300 but I love my st1100 for everyday use so i'm reluctant to give up on her.
Any experts out there i have a bed ready for you . lol
ST1100Y
Site Supporter
He-he, gotcha! :law2:
According to my mech have the smooth edges of the friction plates to face outward
Guess we've ID-ed the cause of your clutch hopping... ;-)
Right, if that is correct, I'll kick my back end round the room - then some beer to celebrate.
I'll change round plates this weekend and let you know
Thanks for your help
Sid
ST1100Y
Site Supporter
Still annoying, removing RHS downpipes, new gaskets needed, etc...
Hope the paper gasket of the clutch cover holds up (it might if you'd greased it during assembly...)
Hope the paper gasket of the clutch cover holds up (it might if you'd greased it during assembly...)
Well stripped down clutch and reversed the metal discs, smooth side to the front.
Still the same problem after a few miles.
From standing start, slipping the clutch on take off and when I fully release the clutch the bite on the rear wheel cushy rubbers can be felt.
Must be the damper shaft ---
Really pissed off now
Still the same problem after a few miles.
From standing start, slipping the clutch on take off and when I fully release the clutch the bite on the rear wheel cushy rubbers can be felt.
Must be the damper shaft ---
Really pissed off now
Wow that is a pain in the neck, good luck finding the problem.
Acaffair: Maybe this can help you....!!! good luck and thanks to share your problem, you gave me some ideas. 
Re: Clutch is slipping when is hot.
Hurrraaaa....?????? Finaly...... the bike is working excelent....!!!!!
I will explain the complete story.
Problem:
Whit cool engine bike work perfect 7:00am... but litle by litle when the engine was hot (normal rate) the clutch start slip and the bike loses traction; if you acelerate start a "crank" sound and "jumping", if you stop the bike don?t move; you need to wait 1 or 2 hrs to be cool and the bike run good again
What hapend..?
Oil..? syntetic..? fluid ..? slave cilinder..?, master cilinder..? clutch..$$$$ ( no please)....?? Deam...
first I thought that of the synthetic oil from yamaha and additives cause the problem and damage the discs, fortunately this was not the cause
Disassembled the Master Cilinder, slave Cilinder, clean all the parts, change the fluid DOT 4 the fluid was damage and caused oxidized sediment, appearance the part were good... after that....!!!!! Bike had same problem.... Deamm... and now..?
Solution:
Al st1100 (thaks very much..) gave me an idea to develop next procedure.
1) Star the engine, Don?t move the Bike.
2) When engine was hot (needle temperature half or more), I put the first gear I start the problem, the Bike didn?t move... to much revolution but no movment.
3) Turn off the engine
4) Pull the clutch handle bar and keep in this position, in the same time released the pressure using valve bleed on the slave cylinder (1/4 turn), carfull the fluid can splash in the face., close the valve bleed and release the handle bar; tight the Valve bleed and release teh handle bar.
5) If the hose is getting presure in this moment you sould have release the extra presure and same time the clutch have bee released.
6) Turn on the engine... put the first gear and surprise.... no more problem... BUT the problem is not over; if you use the next day you will have same issue.
but this helped me to eliminate the idea that problem coming from the clutch, the problemas was on the Master cilinder;
Despite already had cleaned the clutch master cylinder, parts look good, etc for some reason was not working properly.
7) I have a CBR1000F, I change the complete clutch master cilinder, bleed for air on the sistem, pressurizing the sistem... and...no more problem........!!!!!! I have 5 days using in hot condition, trafic, etc... and working perfect.
That confirm that the problem was on the clutch master cilinder but this is a minor problem.
8) open a beer....... is time to celebrate.
Thanks aaaallll the guy who spend time giving me ideas..... thanks again.
My mail if you have a doubt: garrido.braulio@gmail.com
Re: Clutch is slipping when is hot.
Hurrraaaa....?????? Finaly...... the bike is working excelent....!!!!!
I will explain the complete story.
Problem:
Whit cool engine bike work perfect 7:00am... but litle by litle when the engine was hot (normal rate) the clutch start slip and the bike loses traction; if you acelerate start a "crank" sound and "jumping", if you stop the bike don?t move; you need to wait 1 or 2 hrs to be cool and the bike run good again
Oil..? syntetic..? fluid ..? slave cilinder..?, master cilinder..? clutch..$$$$ ( no please)....?? Deam...
first I thought that of the synthetic oil from yamaha and additives cause the problem and damage the discs, fortunately this was not the cause
Disassembled the Master Cilinder, slave Cilinder, clean all the parts, change the fluid DOT 4 the fluid was damage and caused oxidized sediment, appearance the part were good... after that....!!!!! Bike had same problem.... Deamm... and now..?
Solution:
Al st1100 (thaks very much..) gave me an idea to develop next procedure.
1) Star the engine, Don?t move the Bike.
2) When engine was hot (needle temperature half or more), I put the first gear I start the problem, the Bike didn?t move... to much revolution but no movment.
3) Turn off the engine
4) Pull the clutch handle bar and keep in this position, in the same time released the pressure using valve bleed on the slave cylinder (1/4 turn), carfull the fluid can splash in the face., close the valve bleed and release the handle bar; tight the Valve bleed and release teh handle bar.
5) If the hose is getting presure in this moment you sould have release the extra presure and same time the clutch have bee released.
6) Turn on the engine... put the first gear and surprise.... no more problem... BUT the problem is not over; if you use the next day you will have same issue.
but this helped me to eliminate the idea that problem coming from the clutch, the problemas was on the Master cilinder;
Despite already had cleaned the clutch master cylinder, parts look good, etc for some reason was not working properly.
7) I have a CBR1000F, I change the complete clutch master cilinder, bleed for air on the sistem, pressurizing the sistem... and...no more problem........!!!!!! I have 5 days using in hot condition, trafic, etc... and working perfect.
8) open a beer....... is time to celebrate.
Thanks aaaallll the guy who spend time giving me ideas..... thanks again.
My mail if you have a doubt: garrido.braulio@gmail.com
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Well removed the engine and removed gearbox to get access to the damper shaft. Stripped it down measured the spring, all good , some wear on the cam and lifter that i will replace. So far nothing that bad that would cause my problem. Will rebuild but not confident anything will change.
Elmus , I don't have any problems with the clutch slipping, the clutch works great but i'm am interested that the master cylinder could change with the engine getting hot, I've had the master cylinder stripped down and new kit fitted, again could not find anything wrong. But if the master cylinder was somehow faulty it could give me this problem, for sure.
I have an old master cylinder that i will transfer the good parts into and give that a try. Thanks for your help
Elmus , I don't have any problems with the clutch slipping, the clutch works great but i'm am interested that the master cylinder could change with the engine getting hot, I've had the master cylinder stripped down and new kit fitted, again could not find anything wrong. But if the master cylinder was somehow faulty it could give me this problem, for sure.
I have an old master cylinder that i will transfer the good parts into and give that a try. Thanks for your help
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My problem was greater but something I notice is that before have the problem my clutch was also biting, as I mentioned: when accelerating a crank could be heard (when the clutch bite) intermittently in the transmission until I lost traction completely, most likely is when the system begins to pressurize and I my case continuos growing the problem. Good luck.
ST1100Y
Site Supporter
I had feared so...
Back to the hydraulics then...
When you check everything only thing left!, I need night vision glasses as I'm now in the dark. Yep hydraulics.
Okay, I don't know the specifics, but my local Honda dealer told me that years ago they had problems with a bad batch of rear wheel
"spiders" (the five fingered part that engages the alloys in the rubber cush drive).
Apparently some were fitted that were the wrong dimensions and were going too deep into the final drive. Like I say, don't know the specifics, but if you can compare with a known good one, it should be obvious.
I had clutch judder problems and found the metal clutch plates had "blued" with heat and distorted. Replaced offending plates and renewed first and last friction plates... all okay now.
"spiders" (the five fingered part that engages the alloys in the rubber cush drive).
Apparently some were fitted that were the wrong dimensions and were going too deep into the final drive. Like I say, don't know the specifics, but if you can compare with a known good one, it should be obvious.
I had clutch judder problems and found the metal clutch plates had "blued" with heat and distorted. Replaced offending plates and renewed first and last friction plates... all okay now.
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