Hi everyone. Need some help with clutch disengagement issues on XT660X. With the engine in first gear and clutch lever pulled the clutch won't disengage and the back wheel can not be stopped. I tried to take all the slack from the clutch cable without any improvement. The pull lever and casing dots are aligned with the pull lever all the way forward.

I opened the clutch and found out that friction plates are not aligned as per the manual and not in the right order. I decided to disassemble the whole clutch for inspection. I found several things that may not look right

1. After removing the shaft nut I could see that the boss is not all the way in on the shaft splines. I haven't seen disassembled clutch on XT660 so I can not be sure but it does not seem right to me. There are maybe 2 mm from the end of the shaft splines to the front edge of the boss

2. I could not remove the boss by hand. It would move about 3 to 5 mm and then it will stuck. I had to make a tool to force it out. Similar thing on reassembly. It would not go in on the shaft. I had to heat it up and even then I had to force it in

3. The spacer/washer with splines that goes between the boss and the basket is going way past the shaft splines and dangles around the shaft not being in center with the shaft

I reassembled and installed the friction plates in the right order and position, but the issue is still present. The clutch won't disengage. Some of the pressure plates had discoloration like from excessive heat but they were not wrapped. Same thing with the spacer/washer, at some parts there is discoloration.

What could be wrong here? Any advice what to check?

If you want, there is a genuine Yamaha workshop down loadable from the forum baut you need to subscribe . Looka at the main home page.

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I have a lot of growing up to do. I realized that the other day inside my fort.

I do have the Yamaha manual. As per the manual everything seems in order. But it is another thing when you have clear picture of open engine. I also checked the Aprilia manual, there are photos on that manual but not much in detail

Im thick..be gentle..are you saying the suddenly the clutch has stopped working?..or has it become progressively unusable?

The cable itself is 'free'and moves fluidly?..Is it stretched at all?

How old is the clutch?..springs are ok?

You've taken the clutch apartand found that some of the plates show signs of overheating/bluing/wear..and you reused them on the rebuild?..

How much is a new clutch setup where you live?..

I'd take the clutch apart again. Remove the entire unit, springs / pressure plate / friction plates / boss nut / tab washer / then the boss / spacer washer / then the clutch basket.

Check the condition of the splined shaft.

Then put just the boss on the splined shaft without the basket behind it and see if it freely slides up and down the shaft to check for interference or damage between the inner splines of the boss and the shaft splines.

Then check the basket will slide nicely on the shaft, back to where it should sit, by itself and again check for interference / damage between the mating parts. There should be no seizing or need for heating components. In theory these components are not tolerance fitments.

a thing that catches a lot of us out is the alignment of the pull rod teeth and the pull rod shaft regardless of the dots lining up. It has been known for this to go wrong and the pull rod shaft ending up with damaged teeth.

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I have a lot of growing up to do. I realized that the other day inside my fort.

I'm waiting for parts for complete clutch assembly. But before parts arrive I wanted to check if the wrong order and placement of friction plates may be the cause for the issue.

During the reassembly I checked whether the basket goes freely on the shaft. No issues there. No damage, no play, no wear marks on the bushing.

I also tried to slide in the boss with the basket out. No go here. It will not slide at all on the splines. Definitely there is damage but not visible by naked eye. I had to heat the boss to expand so I can force it on the shaft.

What baffles me most is the spacer with splines. According to manual and parts fiche drawings, this spacer should go between the basket and the boss. But when I put this spacer with the basket in, it will go much further then the inside end of the shaft splines. The space between the basket and the shaft splines is larger than the thickness of the spacer. It seats on the shaft part which is smaller in diameter than the part where the basket and boss seat. It will just hang down on the shaft not being in center with the shaft cross section

Maybe I'm doing something wrong but here is how I put back the cover with the pull rod shaft. With pull rod teeth turned to back of the bike I will align the pull rod teeth with the pull rod shaft. While putting back the cover I can see the pull rod shaft rotating.With the cover on, the shaft will rotate freely in both directions till the pull rod inside stops. I will turn the shaft clockwise until the pull rod inside stops on the pressure plate bearing. In this position the dot's are aligned. Then I will attach the cable.

If it does it when the bike is on the rear stand the there will be a little rotation of the back wheel.


When the engine oil is cold (or too thick) the clutch is not fully disingaged (I notice it when pushing the bike)

That is understandable. But in my case, even when the engine is hot, transmission in 1-st gear, clutch lever puled, the wheel will rotate and can not be stopped even if I press hard on it with my foot.

Also, engine off, first gear, clutch pulled, I can not push the bike, very difficult to move the rear wheel.

Does anyone have picture how the boss seats on the transmission shaft?

okay you have already eliminated this so hopefully another member with more experience in that area will be able to help

here's a schematic you may or may not have seen.

https://www.ajsutton.co.uk/genuinepa...9/clutch?uID=0

__________________
I have a lot of growing up to do. I realized that the other day inside my fort.