clutch

hi,thx for answer last time,

but anyone know where i can get a complete new clutch basket ready to go straight in,and cost? in uk, cheers in advance

sorry forgot to add its a 83 xj 750 seca

 

Talk to Len (chacal) at XJ4ever (link at the top of this screen). He does international shipping, and I just got done coordinating an order for new brake lines. He's a real person, and you can ask him questions and actually get knowledgeable recommendations.

info at xj4ever dot com

 

I don't know of anyone, including Yamaha that sells a "complete basket, ready to go in."

Generally speaking, a basic clutch rebuild consists of new friction plates and pressure plate springs. If the original clutch hasn't been abused, then quite often the "steels" (plain plates) can be re-used after a quick cleanup with Scotchbrite.

As long as the basket and hub aren't badly worn, those can generally be re-used as well.

 

What I've noticed on most old bikes you don't even need to change the clutch friction plates. Usually if it is slipping it is because the springs have lost tension. I'd try replacing the springs first to see if it fixes the issue your having, before spending the money on new plates. I also agree with bigfitz rarely will you actually need to replace the clutch basket. I'm not so sure a 750 can make the kind of power to even mess one up.

 

Yes you need to change the friction plates. They become "petrified" with dried oil after sitting for a long time and begin to slip and/or crumble once heated up again; long before they wear out.

 

the springs and friction plates are equally important, they work together.
you can skip the bolts, there's nothing special about them, just use thread locker on them

 

Since I got 2 "wizards" here I might as well ask a related clutch question. Do yamaha's have issues with the springs on the back of the clutch basket rattling at low rpm?it kind of sounds like a rod knock. It's a chronic issue on suzukis, and i've seen it on kawasakis as well. Sorry I'm new to yammies but not new to bikes.

 

i have a sv1000, i know about clutch "chudder"all to well.
i've never heard it on my yamahas and never read about it on here

 

cheers for replies
bike didnt slip till i had it serviced,and carbs done,the chap put wrong oil in it and it slipped like mad,so i changed it with new 10/50 mineral oil,now it only slips now and again, is it worth just changing the springs? thanx

 

there's a spec in the book for free length.
when i had my maxim i had some slip even though the friction plates measured new, put new plates and still slipped, changed springs and it never slipped again.

 

this is why you should use thread lock juice

 

Thanks.

 

It's quite an issue on Hondas too, usually balancing the carbs makes it less noticeable... our XJs must just be too smooth for it to happen, plus they have a slightly different system than the coil springs that go slack. 8)

Quote taken from the Haynes 650/750 manual "The clutch centre incorporates a spring shock absorber to damp out snatching or chattering as drive is taken up. The innermost plain plate is held in place by a large wire retaining clip and beneath it lies a thin diaphragm spring and a spring seat. It is unlikely these components will need to be disturbed unless severe clutch chatter has been evident"...

As far as nobluff's issue, I'd try changing the oil again before condemning the clutch if it's only happened after the synth was used. there's quite a lot of oil gets left in an XJ when you drain the sump (think someone mentioned 7 ounces), so it might be worth a try. Remember to use no higher than API "SG" too as even higher rated mineral oils have more additives, Yamaha spec was "SE".

 

IF THE CLUTCH IS THE 30-YEAR OLD ORIGINAL IT SIMPLY NEEDS TO BE REBUILT.

"Sooner rather than later" will simply make the job less expensive.

 

OK Not saying 30yr old friction materials *shouldn't* be replaced, but maybe it already has been if it wasn't slipping before synthetic oil was used. All I was saying was it might help, and a gallon of oil's cheaper than a clutch rebuild. If it doesn't work you're only out half a gallon of oil, use the other half to replace the oil when the plates & springs get swapped.

 

RE: oil. Motorcycle-spec, 20W basis-weight either 20W40 or 20W50 unless it's regularly below 40 degrees (F) then it's 10W30. I don't know of any motorcycle-spec oil that comes in gallons.

RE: clutches. I said "original." If it is the original clutch, it's not OK nor will it be. Original clutches dry out from sitting and the once oil-bathed friction plates literally become little squares of linoleum. Once back in service, they may seem to work for a while before obvious slippage is noticed; but once it happens putting off remedying it just makes the fix more expensive (new plain plates.) It's not a case of "maybe" or "might." Twenty plus years of sitting and they do dry out, without exception.

 

I know, and I'm not going to argue with you on it, just saying it's possible the clutch is not the original one & for the price of a gallon (well ok if I want to be exact, they sell them as 5 litres now but what's 450ml between friends? :lol: ) of oil I'd change it one more time & see if it stopped slipping or not.

I never denied that a 30 year old clutch or any clutch that's stood a spell dries out & dies, because you're right it does. But at the end of the day, if the clutch has already "slipped like mad" chances are any overheating of the plain plates is already done on that first ride & a few more miles on fresh oil won't hurt them any more than they already have been when it was at it's worst, especially if it does happen to stop the slipping.