3YF-'91 General Overhaul

[Worthlessbilly]

Hi, as I've realized that there are probably going to be a LOT of questions whilst I try to get my bike to the stage that I want it (back on the road for a start) I thought it might be better to put my questions/begs for help all in one post.


Please understand that I'm new to riding and this is the first bike I've owned. I'm sure some of the jobs I'll be attempting will be way beyond my knowledge factor but a) I don't have the money to pay a professional and b) I think it's a good way to get to know the bike/bikes in general.


Currently I'm trying to replace the clutch plates and springs. The problem is I can't get the clutch cover off. I've drained the bike, removed all the securing allen bolts, including the rearward one that I had to take off the rear brake pedal to get to. I'm reticent to apply too much force or try and pry it off with a flat instrument as I'm aware that it's gasketed. It there a particular technique to removing the cover, or a particular place I should apply force to? Whilst I'm happy to give anything a go, I don't want to break it.

Thanks in advance for any help,
Billy

[Worthlessbilly]

Right, sorry to be a time waster re. the last question, I was being dense and forgot to remove the bolt inside the water pump. Once I looked at a pic of an open clutch case I could see my mistake.


Anyway, as I suspected the clutch (or at least some of the plates) are fragged. Do I need to replace the whole lot as with chain and sprockets or can I just replace what's damaged as the other stuff seems pristine. I'll put up some pics of the respective parts...

[Worthlessbilly]

Right, he's dead as disco. That much I know at least...



Same for these boys, although it's hard to see the one at the back is in similar condition to that of the foreground.



These (Spacers?) look pretty worn to me, and I assume they would be a bin job but every penny helps so if I can keep using them please say?




What about these? They're still smooth but one has slight discolouration. The pad marks are visible but not tangible, so keepers?

And finally these (plates?) they appear OK to me, the (Friction pads?) are still clearly defined but I don't know how thick they're supposed to be?

Thank you in advance for any help/advice. Please also tell me if any of the (terminology?) I've used is wrong. Like I said I'm a at this and am here to learn from experience.

Sorry for the long post: Billy

[Worthlessbilly]

Also LAAAST question for now I promise: Are there any other clutch baskets that will fit or does it have to be specific to this particular bike? I just had a, seemingly quite expensive slip of the hand and now need a new basket (well the inner bit with the 5 cast prongs inside.

TIA, Billy

[xtrider]

You will need to buy the complete clutch discs as a kit. There are several companies that offer them, make sure the kit includes both the fiber discs and the pressure plates( EBC, Burrnet, ect..) , yours are not usable, OEM suppliers will be fine also .

There should be a ring , it looks like a big snapring, also and 2 of the pressure plates will have a bigger inside diameter, those parts go on in a certain order.

As for the basket, I'm not sure but I believe the basket is the same on most of the 600 xt's, just keep to the general years you have. I will try to cross reference some OEM numbers the make sure, otherwise there are several members here that will know for sure ( MEZO , hello, where are you?? hint, hint). While your ordering the plates and discs, be sure to get the case gasket, so it doesn't leak once back together. Ebay might give you the entire clutch, check there also, but I personally would buy new.

Are there any grooves in the outer basket where the discs ears go? If there is some decent grooves then you will need the entire clutch set-up to prevent a sticky clutch, which will cause all the heat issues you seemingly had. My guess is someone used the wrong oil and the clutch was constantly slipping and it attacked the fiber on the discs. Probably was stuck tight together after sitting awhile and shattered them when breaking free. I bought a Honda xl600 that the guy used normal oil in, every time it sat for even a couple days, the clutch plates wouldn't release, often choking the motor. I drained all oil and replaced with a good full syn motorcycle oil made for wet clutches and it all went away.

[Worthlessbilly]

Thanks a lot mate, if you get a chance that'd be ideal as I want to save as much as possible having put a fair bit of money in to an initially cheap bike. I'll hang fire and see if anyone has anything more definitive before ordering as little'un + sun = no bike playing being done this weekend any way.

Are the pressure plates you're referring to the smooth rings that I pictured? I think I called them "spacers". I'll bear in mind the order and will refer back to this and elsewhere when refitting.
The outer basket SEEMS ok, as does the case barring a lot of swarf. I'll put up the only pic I have for now but have a better nosey around next time.

As for the culprit, I may as well put my hands up and say it's most likely me!

I think the bike had stood for about a year before I bought it, then the combination of a new rider, with perhaps questionable clutch control, trying to off-road up a pretty steep lumpy incline on a fully loaded bike (I can't think of any more excuses to hand) was probably a contributary factor.

Just for my future reference, how can you tell if the clutch plates are worn just by looking? It it any deformation of those (Friction Pads?) or does there need to be a certain tread depth as it were?

Cheers for your patience all,
Billy

[Worthlessbilly]

This is the piece I broke, like the passion fingered (Cheers Australia for such a succinct and elegant phrase) twat that I am. Everything else APPEARS to be in order on first inspection though.

[xtzrick]

That's the 1st bike clutch I've seen do that, well done

What does the top pressure plate look like?
If it's scratched it's knackered & it would be cheaper to look for a complete 2nd hand clutch.

Not sure about XT600s but SZR660s use the same clutch, 4MY (the twin headlight XTZ660s) clutches look similar apart from they use steel spacer plates, I'll check on saturday to make sure they are the same & inter changeable.

Rick

[xtrider]

That is the inner clutch hub that is broken and that's the piece I was asking about having grooves in so since you need a new one, it doesn't matter. My XT has the steel spacer/pressure plate and the fiber plates are steel with the fiber bonded to them (IIRC). Ebay has a bunch of entire units for about $100 us dollars.

As far as knowing if the plates are bad, I can see yours are discolored and have been getting hot. The steel spacer/pressure plates should be smooth and normal silver/bare steel looking and perfectly flat when layed on a true surface. The fibers have those grooves and you go by the debth of the grooves or lack of them.

If your bike sat for a year it's likely the fiber pads dried out got brittle from not being bathed in oil, then when put under stress they just broke. Could be that earlier in the bikes life the plates were replaced with a cheap brand, you never know with used stuff. So far I haven't found any difference in clutches on the XT line, they have been the same one. And most likely used in a number of other models ,like XTZrick pointed out.

[Worthlessbilly]

Cheers Rick, I do try to excel at incompetence! I've looked at the pressure plate, everything's cool and everything's smooth including the little race of roller bearings.

Right I got a used inner clutch hub from ebay for 25 quid delivered and a set of new EBC friction plates and Lucas spacers. There only thing is; a minor segment of the outer circumference ring on the back is a little undulated and as some surface cracking. I'm not really sure what it is, maybe a bit of corrosion or some other sort or impurity in the casting?

The edge surface (if you were looking at the unit directly side on) is smooth and good and the face circumference is likewise. On the square splines there are three pairs of wear about .5mm deep. If you were looking at the hub face on they would be in the relative positions of 12, 4 and 8 oclock (or like a mercedes logo).

Pleeeease tell me it's usable, we're running out of sun here!

I'll try and upload a pic in a bit, I've just read beck my description!.......