Mirage slipping clutch

N

neandethal

Junior member
Location
oakham
Hi folks,

After a few weeks of non use i took my mirage out for a run, and for about the first 10-15 miles the clutch was slipping when giving it some beans. after this time it settled down and was fine. Is this usual if they have been stood or is this an early signs of a repair/work being imminent?
Thanks for any info shared. Regards Ian
 
you will very likely need a new set of springs and bugger all else, easy job to strip the primary on a Mirage, no hassles at all, drain oil , loosen chain tensioner, undo bolts take cover off, (if it sticks get back to us,) undo the crankshaft jesus nut (locking tool required) unclip the circlip on the centre of the clutch drum, lift off engine sprocket and clutch chain wheel with chain in one unit, undo three clutch pressure plate bolts and change three springs then undo the other three and change the others, reverse order and you are done, new locking washer, and loctite for the jesus nut, tight as a circumcised person wearing a weird hat in a financial crisis, replace clip on clutch drum, new gasket on clean surfaces for the cover, re-adjust primary chain and finished.

If you really must take out all the spring bolts at the same time because you feel the need to inspect the plates, then getting them lined up again can be a PITA, a tool is available which makes life easy, but without it is still achievable just fiddly and frustrating!

This assumes that the cable (if so fitted) is routed and lubed well and is not causing a momentary slow release, or that the two pushrods and their centre ball are not doing the same, and (maybe) the hydrauilc cylinder is hanging up (again if so fitted)
CLEM
 
Thanks Clem. I'm beginning to think I bought a Friday afternoon bike! blowing exhaust gaskets and now this in less than 200 miles, makes my Ducati's look awesome for reliability. 😂 Its a hydraulic clutch not cable, and I wonder if the pushrods are just sticky from lack of use, might try using twice a week for a while and maybe change the oil before diving into the innards, and buying special tools etc. or trying to make one.
What's the consensus on best oil, maybe what's in it is a tad thick??
 
Only time I've ever had slip on mine was after I first tried a semi-synthetic oil.
I stripped out the clutch plates, washed them with petrol, deglazed the friction plates and re-assembled. Problem solved! Hopefully the DPO hasn't used that.
I ran mine, for forty years, on Duckhams 20/50 Mineral Oil. Valvoline VR1 Racing 20W-50 for the last five but, enough of that.
Put "oil thread" in the Search Box (top right if you're on a PC) and you'll see the can of worms you've opened!

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neandethal said:
Hi folks,

After a few weeks of non use i took my mirage out for a run, and for about the first 10-15 miles the clutch was slipping when giving it some beans. after this time it settled down and was fine. Is this usual if they have been stood or is this an early signs of a repair/work being imminent?
Thanks for any info shared. Regards Ian
Click to expand...
What you describe isn't normal. By all means try an oil change, per Hamish's suggestion. Doubt it's sticking pushrods, given previously OK. I'd suggest removing the hydraulic cover and check slave cylinder piston operation. The alloy housing can/does suffer from corrosion which may affect operation.
 
She has a Wet Clutch - DO NOT use a Teflon additive or Synth Oil - You can fix the clutch pack after as mentioned above by washing with say Laquer thinner and burning the disks off with a torch and scuffing with say 220 grit. Stick with a Diesel 15w40 DINO Oil that Truckers use.

After disassembly and cleaning the clutch pack and refilling the case with DINO - DO NOT over tork the basket bolts holding the clutch pack in as they easily strip. It's about 10" pds not FT pds - Check the torque specs.
 
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those crank locking tools work great, but they are angular and not pleasant to look at or use, dont let that stop you buying one, they come without a socket, and you may well find that the ones you already posses do not have the correct outer diameter to work with the tool, not difficult to sort, but just warning you, and a six pointer is HUGELY preferable to a 12 pointer, that nut has to be tight! and if its easy to get off, take a look at the crankshaft splines for wear.

quote from Rob
"What you describe isn't normal. By all means try an oil change, per Hamish's suggestion. Doubt it's sticking pushrods, given previously OK. I'd suggest removing the hydraulic cover and check slave cylinder piston operation. The alloy housing can/does suffer from corrosion which may affect operation."
I agree entirely Rob, but usually when this happens the slave piston will come out and do its job, but stays stuck half way, or less, on the way back in, what we have here, if I understand it correctly, is a momentary slip, which recovers, springs I say, the ones installed just can't cope with a slight surge in torque. You don't have to be riding the bike for the springs to wear out, they are under compression (the pre load) and if the bike is idle for any length of time, or ridden daily, they will soften at more or less the same rate, its weird that a ridden bike seems to have longer lasting almost everything including clutch springs.

CLEM
 
Not to highjack this, but comments in this thread sparked a question. Do recent formulations of synthetic oil really cause clutch slip? I know that early on some found syn. oil escaped seals that had previously held dino oil. That has changed with new oils. If that's the case, why wouldn't the proper synthetic oil allow wet clutches to function as they should? There are metric tonnes of Japanese motos with wet clutches. Do all their owners need to avoid synthetics if they want clutches that work? It's been said many times here that the old Laverdas need to run on what they were designed to run on. I'm not sure I'm convinced of that.
BTW, I love my Mikunis and Witt. :D
 
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I used Mobil 1 in my SF - brilliant oil, absolutely no doubt - clutch never slipped.

Oh dear - is that an oil thread i can feel creeping up behind me!!! 😧
 
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