Project "walrus" Yam XS 750

Re: Project "walrus" Yam XS 750

How much oil would you guys drain in order to work on the left side?


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How much work are you doing? Sometimes, I just put the bike on it's side and don't drain anything for in the field repair.

irk miller said:

How much work are you doing? Sometimes, I just put the bike on it's side and don't drain anything for in the field repair.

Click to expand...

Thought about that too but since i dont know how long the bike will stay in that position (i need the check which seals to refit and order them)
My money is on a worn pushrod...hope the replacement will be here end of this week.
i guess I will need to drain some...the bike has around 3 litres of oil...

Re: Project "walrus" Yam XS 750

If you remove the clutch cover usually just a bit more lean than on the sidestand will be enough

Right hand side was no problem with the bike on the sidestand.
As for the left side, which I will be working on this weekend I hope it will be sufficient to drain 1-2 litres of oil,guess it would be better to drain all oil, refill the oil filter housing and then refill all the oil.

As for the crank pin, I guess I will settle on putting a small ball bearing behind it to keep it from retracting and making a fool out of me

Have you guys already exchanged the pushrod seal on your XS´s?
I guess I will need to carefully drill a little hole into the seal then use a wood screw to pull the seal.
Made a little research--> It is really important to debur all surfaces that touch the new seal,or it will leak, the seal is a special make since the pushrod spins freely and transports oil, the seal has a slight "turn" to hinder oil from dripping out of there.

Just ran into this interesting Yamaha sheet, showing how the factory already struggled with the design of the pushrod-seal...looks like the vibration caused by the pushrod caused these issues...thats why they retrofitted bushings ...see here:

http://www.yamahatriples.com/files/3413/5405/0315/77e_003_oil_leak_clutch_pushrod.pdf

I built mine from scrap and parts so all new seals there
No leak yet but i wasnt aware there was excessive clearance between pushrod and axle. Must have already been fitted with a bush.

Hey guys!

So I had a week-end full of work on the XS750:

-Removed ignition plate (XS 850 ignition type)
Pretty easy and straight forward,I used a wrench to carefully turn the nut till the lobe was aligned with the opening in the ign.plate then removed the 3 screws with the plate, then I removed the advancer mechanism which is "aligned" with the crank pin (was already welded in by the PO, so no problemo there )

-Checked the pushrod
The pushrod had little wear marks (nothing I would consider as problematic), the pushrod seal was replaced by (I will need to redo that, since I broke the seal when I drove it in,misaligned...)

-Cleaned and re-greased the clutch mechanism
It was not that easy to get all the little steel balls back into place, but after a few trys it worked.

So I ended up with a slighlty better clutch situation but with a leaky pushrod seal :'( ....this needs to get fixed next weekend.

Had some time to call the PO:

He told me to:
-Clean and check the clutch plates (steel and friction)
-Clean and dissassemble the clutch dampener (can this really cause this issue???)
-Check for the steel piece thats pushed against the clutch plate with the steel ball (if its positioned right and if its free to move)
-Check the pushrod for free movement
-Check for wear on the basket-->There is light wear on the baskets-->how would you guys dress this wears down?

So I guess I will need to make a full left and right hand side tear down next week-end....

Re: Project "walrus" Yam XS 750

Hi Ryan
In the clutch actuator with the little ball bearings did you check that there was also a larger 6mm ball that takes up the thrust of the pushrod when you pull the clutch?
If it has fallen out the clutch will not work!
Cheers
Tim

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Re: Project "walrus" Yam XS 750

Hi Tim!

Yes,the steel ball is inside.
And the assembly is freshly greased.
Guess I need to check the clutch side AGAIN :-(.

-checking steel plates for warpage
-checking friction plates


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I bet a pint that the steelies aren't warped. (Because we checked them together, remember?)

Re: Project "walrus" Yam XS 750

I know Nanno!And the friction plates too!This thing is driving me mad

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Course it does... it's what those old girls do best. ;D

So i settled on checking AGAIN everything plus changing the friction plates for fresh OEM ones (the PO gave me six of them,so i'm lucky) plus new clutch springs (also from the PO).
Clutch pushrodseal needs an exhange and I will put on two new gaskets for the cases since the ones now are in bad shape.

Lets see if the gods will let me have freedom finally

Hi Ryan
The clutch will not release, is that correct?
Have you checked that all the plate washers are there and have not been replaced with a dodgy alternative? Ref #23,26,31 &32
From my understanding assembly #17 is held in a fixed position and then the pushrod moves #13 away to allow plates to slip. So if a washer is missing there may be additional free play that cannot be taken up could be the problem.
The clutch actuator mounting can also be f'd up - I have done it (had the engine stripped for 12 months before reassembling)! There is a small alloy housing on the inside of the side cover that is held on by 2 screws that mounts the clutch actuator to the side cover. If that is put on the wrong way there is not enough adjustment to actuate the clutch!
Good luck
Tim

XS750AU said:

Hi Ryan
The clutch will not release, is that correct?
Have you checked that all the plate washers are there and have not been replaced with a dodgy alternative? Ref #23,26,31 &32
From my understanding assembly #17 is held in a fixed position and then the pushrod moves #13 away to allow plates to slip. So if a washer is missing there may be additional free play that cannot be taken up could be the problem.
The clutch actuator mounting can also be f'd up - I have done it (had the engine stripped for 12 months before reassembling)! There is a small alloy housing on the inside of the side cover that is held on by 2 screws that mounts the clutch actuator to the side cover. If that is put on the wrong way there is not enough adjustment to actuate the clutch!
Good luck
Tim

Click to expand...

Thanks Tim for your insight!
I will tear the clutch apart this weekend and I will have a deeper look if this washers are missing, since the PO also forget the big spring clip on the outside iof the dampener, one could assume that more can be missing inside this clutch....

Concerning the clutch mechanism: I completely stripped it, cleaned and greased it (all steel balls in place).
IRC there are two JIS screws holding the actuator to the case, do you mean when the assembly is "flipped" (mounted on the wrong JIS threaded hole) the whole thing could not "engage" enough?
I have some pics of the assembly before cleaning and after, I was really carefully and marked how it was originally mounted....maybe the PO effed up.

Oooooh and I forgot the following:

I made a little video of the clutch movement the first time I dissassembled...Is it normal that the pressure plate doesn´t fully move onto the snap ring like seen in the video...maybe this is the missing "reach" we are talking about...
https://www.youtube.com/watch?v=nI1d6FMYn-k

The amount of motion in the video looks fine. The fact that the pressure plate does not contact the snap ring is ok - there is no need for it to do so. If you don't have the same degree of motion now I would look for a problem in the actuator first. The actuating crank in the last picture looks like it is in the wrong position. When the crank arm and cable are at 90o to each other, usually that is the midpoint in the rotation of the arm. Don't be confused by the shape of the arm, imagine a straight line between the center of rotation and the swivel pin for the cable as the arm. I would expect that it should be 20o-30o counter clockwise from the position in the pic when the return spring has it fully retracted. Perhaps the mounting casting needs to be swapped 180o as previously suggested to get it in the right position.

Hi Ryan
The other indicator that the actuator housing is the wrong way, is that the adjuster lock nut is very difficult to get a socket onto the nut. The lock nut should be prominent and easy to get a socket on, when the housing is the wrong way the nut set back and recessed deep into the actuator!
Sounds like to PO had a problem with the clutch if there are spare plates and missing clips, so I guess he could have pulled the actuator apart also - you just never know! Very simple job to swap it over and see if you get any improvement.
Cheers
Tim

Thanks mobius and tim for your precious insight!
Is there a way tim that you make a pic of your adjustment screw for me to see how far it protrudes?

Made 2 pics one of my adjustment screw how it sits right now.
And one of from the top with clutch fully pulled in,does your pushrod look like this when fully pulled in tim?
Thanks!



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Hi Ryan

I had a look at your video - the clutch appeared to actuate correctly! Did you actuate it using the clutch handle bar lever, or some other way?

Please see below the photos of the adjuster screw on the XS750, which has had the engine completely disassembled for hydroblasting and rebuild. I did not remove the clutch cage from the shaft during rebuild as it was OK. That was the one I had the housing the wrong way round! The 750 is very clean in photo!

The other photos are of the clutch on the XS896 build. This was the first time I have removed the cover, and give that that engine has probably done less than 100hrs in it entire life, it would be the factory adjustment! This is the dusty photos - first time to remove the cover!!!

Both look very similar as far as adjuster screw projecting out of lock nut. Hope it helps.
Cheers
Tim

Ryan
Sorry forgot the photos of the rod - attached below.
From your photos the housing is the correct way. Adjustment is similar, in that you have 5 threads showing on adjuster screw, my 750 has 6 threads showing and the 896 7 threads (once again indicating that engine has done bugger all work).
It is looking like the actuator is OK, so I guess it is back to the clutch cage. I have not had to rebuild the cage so will not be much help. Remember reading somewhere that there was a cork faced pressure plate that must be in the correct location - see if I can find the reference.
Good luck.