Andi Posted February 27, 2023 Posted February 27, 2023 (edited) Sorry for such a long post but this has been a long term problem that I have been trying to fix for a looonnngg time. It feels like the clutch is slipping upon acceleration, especially in lower gears and higher speeds are generally not possible. So far I have changed clutch plates going from EBC to original ones. Replaced both the inner and outer clutch baskets and fitted heavy duty springs, all to no avail. I remembered reading somewhere that one of the gears can spin on the shaft so I looked in the workshop manual and found out that the 2nd drive gear is a press fit on the layshaft. It also states that this gear can be replaced twice before a new shaft is required. Has anyone else come across this problem and come to the same conclusion that the clutch isn't the issue? Any help or suggestions will be more than welcome. Edited February 27, 2023 by Andi Quote
eddiegsx Posted February 27, 2023 Posted February 27, 2023 Hi Andi and welcome to oss, what oil are you using? Apologies if you've already covered that one. Quote
Andi Posted February 27, 2023 Author Posted February 27, 2023 I had been using a semi synthetic but reverted back to a fully mineral in the hope that it had something to do with it when I was convinced it was a clutch issue. Quote
coombehouse Posted February 28, 2023 Posted February 28, 2023 (edited) I had an issue for many years with clutch slip (like 30 years on & off!) I finally found the problem last year when replacing the plates yet again. I noticed looking through the drilled holes in the pressure plate ( these were an addition on later engines) that there was very little clearance before the pressure plate bottomed out on the inner basket, thereby preventing the springs doing their bit. I messed about with some slightly thicker plates to increase the clutch stack height & problem solved. I should have spotted it years ago but I have no idea why it happened in the first place. Tolerance buildup maybe, who knows but it's worth having a really good look & measuring everything. Edited February 28, 2023 by coombehouse Spolling Quote
rodneya Posted February 28, 2023 Posted February 28, 2023 27 minutes ago, coombehouse said: I had an issue for many years with clutch slip (like 30 years on & off!) I finally found the problem last year when replacing the plates yet again. I noticed looking through the drilled holes in the pressure plate ( these were an addition on later engines) that there was very little clearance before the pressure plate bottomed out on the inner basket, thereby preventing the springs doing their bit. I messed about with some slightly thicker plates to increase the clutch stack height & problem solved. I should have spotted it years ago but I have no idea why it happened in the first place. Tolerance buildup maybe, who knows but it's worth having a really good look & measuring everything. Ive seen people run two steels at the bottom of the pack to increase stack height. 1 Quote
Arttu Posted February 28, 2023 Posted February 28, 2023 Your problem sounds slightly vague. Usually when the clutch slips it's most noticeable on high gear at maximum torque rpm, something around 5000-7000rpm in EFE case. You can try blipping the clutch quickly at full throttle there and try to feel it graps right away when you release the clutch or if it slips there. I have also heard that the 2nd gear can get loose on the shaft but haven't never vitnessed that. I would assume it isn't recovering when it lets go. Quote
Duckndive Posted February 28, 2023 Posted February 28, 2023 7 hours ago, rodneya said: Ive seen people run two steels at the bottom of the pack to increase stack height. Common Drag Race trick but To do that you have to mod the inner hub by removing the lip at the bottom along with the clip and steel Quote
Andi Posted February 28, 2023 Author Posted February 28, 2023 8 hours ago, coombehouse said: I had an issue for many years with clutch slip (like 30 years on & off!) I finally found the problem last year when replacing the plates yet again. I noticed looking through the drilled holes in the pressure plate ( these were an addition on later engines) that there was very little clearance before the pressure plate bottomed out on the inner basket, thereby preventing the springs doing their bit. I messed about with some slightly thicker plates to increase the clutch stack height & problem solved. I should have spotted it years ago but I have no idea why it happened in the first place. Tolerance buildup maybe, who knows but it's worth having a really good look & measuring everything. That's something I haven't thought of. I know that there is a set of clutch plates for it with extra plates available, think APE do them, so that could be a way to go. I have measured the steel plates and they are well inside tolerance. Quote
Andi Posted February 28, 2023 Author Posted February 28, 2023 (edited) 3 hours ago, Arttu said: Your problem sounds slightly vague. Usually when the clutch slips it's most noticeable on high gear at maximum torque rpm, something around 5000-7000rpm in EFE case. You can try blipping the clutch quickly at full throttle there and try to feel it graps right away when you release the clutch or if it slips there. I have also heard that the 2nd gear can get loose on the shaft but haven't never vitnessed that. I would assume it isn't recovering when it lets go. Its quite noticeable in 1st gear under hard acceleration. No pulling your arms out of their sockets and will not get much above 25 before you have to change up. Also if you crack open the throttle in any gear there's no real pull, just a gentle acceleration. Top speed is not far above legal limit. Rev counter also hunts and doesn't move in relation to speedo. Edited February 28, 2023 by Andi Quote
Duckndive Posted February 28, 2023 Posted February 28, 2023 (edited) If it has been slipping as you described for some time then the fibres will be F##ked by now. anyway... The Semi Synthetic may not have helped the situation IMO There is no reason a stock clutch needs any extra bits on a stock engine ....OEM Parts are the best Back to basics strip and investigate Soak new Fibres overnight in Mineral Oil before fitting .... Edited February 28, 2023 by Duckndive Quote
Gixer1460 Posted February 28, 2023 Posted February 28, 2023 I'm with Arttu on this one - I can't see the second gear being a problem (I'd never heard about that problem !) particularly as this is happening in 1st gear ! And as said, its not occuring where usual slip occurs. So, I believe this is more of an engagement issue, like, although the lever is fully thrown and clutch should be 'locked' somewhere between the handlebar and the clutch pack there is a hang up stopping full engagement - something like bad adjustment / cable too tight or what I suspect - a frayed cable inner somewhere? I'd try a different cable, if only to elliminate that? Quote
Andi Posted February 28, 2023 Author Posted February 28, 2023 1 hour ago, Gixer1460 said: I'm with Arttu on this one - I can't see the second gear being a problem (I'd never heard about that problem !) particularly as this is happening in 1st gear ! And as said, its not occuring where usual slip occurs. So, I believe this is more of an engagement issue, like, although the lever is fully thrown and clutch should be 'locked' somewhere between the handlebar and the clutch pack there is a hang up stopping full engagement - something like bad adjustment / cable too tight or what I suspect - a frayed cable inner somewhere? I'd try a different cable, if only to elliminate that? It's a new cable and there is play in the pinion lever when clutch should be engaged. I will strip down clutch and inspect everything to see what I can find. 1 Quote
coombehouse Posted February 28, 2023 Posted February 28, 2023 12 hours ago, Duckndive said: If it has been slipping as you described for some time then the fibres will be F##ked by now. anyway... The Semi Synthetic may not have helped the situation IMO There is no reason a stock clutch needs any extra bits on a stock engine ....OEM Parts are the best Back to basics strip and investigate Soak new Fibres overnight in Mineral Oil before fitting .... I've run all sorts of oil over the years, car oil, mineral, semi & fully synthetic. Never seemed to make any difference at all to the clutch on any bike I've owned. Quote
Duckndive Posted February 28, 2023 Posted February 28, 2023 10 minutes ago, coombehouse said: I've run all sorts of oil over the years, car oil, mineral, semi & fully synthetic. Never seemed to make any difference at all to the clutch on any bike I've owned. Well done you .... hence why i put IMO Only ever use cheap Mineral in all my GSX motors never had any issues Quote
coombehouse Posted February 28, 2023 Posted February 28, 2023 (edited) 44 minutes ago, Duckndive said: Well done you .... hence why i put IMO Only ever use cheap Mineral in all my GSX motors never had any issues We will get banned mentioning oil though. Best leave it there Edited February 28, 2023 by coombehouse 1 Quote
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