'75 Fork Piston Confusion

[REPETE]

Good Morning All from your newest member!
I have been reading and gathering information from this site for a couple of months and figured it was high time I joined... and donated to that from which I benefited. Done and done!
Now, I have a conundrum that I do need to request direct assistance with.
I am prepping a '75 XS650B for road worthiness after it had been unused for 23+ yrs. I've been methodically going through it - both mechanically electrical - so I can enjoy riding it prior to one day doing a total restoration. We'll call this a "preservation"
Here's the dilemma... two parts.
Minor part: somebody (not surprisingly) has had these fork tubes apart before. When the fork tube caps were removed six washers fell out. Presumably they were riding atop the spring just under the cap. I can't imagine why they'd be there but it was obviously somebody's fix. Is this a known shade tree mechanic fix for something known to occur within the fork tube. i.e. does the spring eventually lose length from years of usage?
Major part: like many, when I removed the piston from the bottom of the upper tube, parts hit the bench and bounced a bit out of position. I thought I was able to figure out the proper sequence of parts, but when trying to verify by researching the issue on the site I came up with a photo that was contrary to what I believed correct. Unfortunately there is no diagram available that shows the proper order of stacking for these parts.
I've attached (I hope properly) a side by side picture I prepared. Issue is with the spring and castellated(?) piece.
I'm sure hoping someone that has direct & definitive knowledge of this can get me on the right track.
I sure would appreciate it.
Thank you

 

[DogBunny]

The assembly on the right in your picture looks right. Here are pics showing correct assembly:

 

[5twins]

Yes, it appears someone added that stack of washers to the top of the spring to preload it more and stiffen the forks up a bit. Usually you add a tube spacer, the length of which may take some experimenting and measuring. You don't want it too long or the spring will fully compress and become coil bound before the fork is fully compressed. Too short and it won't stiffen the forks enough for you.

I went through all this on the later forks, compressing a spring fully on the work bench to determine just how much travel it had. I came to the conclusion that I could safely add about a 1" spacer. I proceeded to do up the set of forks on my current project but after running it all summer, I think I've made them a little too stiff. What I didn't take into account was the thickness of the washer I added under the spacer tube, so it seems I've preloaded them a bit more than an inch, maybe closer to 1 1/8".

So, I have more experimenting to do. I will probably shorten the spacers a little bit, and play with the amount of fork oil (slightly less) to reduce the air spring effect some.

 

[REPETE]

I want to thank you both very much. The info. will allow me to keep moving forward.
DogBunny - for the record (humility here) my parts stacking was the picture that was wrong!

5Twinns - as I had written, I've been studying the XS650.com site for awhile prior to joining and admire the knowledge you and other frequent contributors share. I'm going to take the tack that there's nothing wrong with my spring and that the washers were there in an attemp to pre-load it a bit. Funny thing though is that it was only on one side.

Being that the fork is still disassembled, is there an overall length of the spring that I should be checking?

Thank you (both) again

 

[5twins]

A free length for the later springs is given in the later manuals but I don't see any listing for your early fork in the early manual. But, the parts diagrams do show a long spacer tube used with the spring (#17) .....

https://www.partzilla.com/catalog/yamaha/motorcycle/1975/xs650b/front-fork-tx650a-xs650b

Not sure if all the early forks had this. It looks to be quite long so I would think you need it if the spring is original. Unless maybe Yamaha changed to longer springs on some models. Usually, the spring and any spacers installed in the tube will come up to or nearly to the top of the fork tube. If you don't have the spacer tube and your spring sits down into the tube several inches, I think you need the spacer. Here's my later fork with the spacer added. It comes right to the top of the tube .....

 

[REPETE]

Yes. Spacer tube is present as is the "upper seat spring washer" that sits atop the spring.
So, looks like I'll reassemble and move forward confidently.
I appreciate the input.

 

[DogBunny]

Here's an old pic of a 1975 spring. Kind of hard to tell exact length because of camera angles. Probably somewhere around 15-1/4". Take a look at the ends, if the spring was shortened (unlikely) it should show. Also very unlikely that the average previous owner had another set of springs laying around to swap in.
When reassembling the tight coils go up.

 

[5twins]

That top hat shaped spring washer is rather unique. I like the way they fit down into the spring and stay centered. I see MikesXS sells a replacement aftermarket progressive spring for the early forks. My added spacer experiments were an attempt to save the cost of new springs. I like the originals but most seem to be just a bit too soft. If you find your springs too soft, maybe making some new slightly longer (1/2" to 1") spacer tubes might help, and save you the cost of new springs.

 

[REPETE]

I think I’m ok on the spring length. It’s 151/2”. So looks good there.
I’m down to one final question (I hope).
Concerning the piston itself, there’s a chamfered end and a straight edged end.
Which end faces “up” in the fork tube against the pieces we discussed earlier?
All the little details that can derail you!

 

[REPETE]

DISREGARD! I figured it out!
Chamfered side down

 

[5twins]

I can't answer that one but I do think you needn't remove those couple parts from the fork tube in the first place to get the damper rods out. You just "dump" them out the top.

 

[thuban]

Repete,
I edited that out. If 5Twins can't help you it won't get done.
I ground the sides out of a 1/2 -11/16 socket to hold the "hat" nut and used 2 - 1/2 X 12 inch extensions to hold it.

 

[REPETE]

Thuban -
I’m pretty sure I’ve got it.
The pieces in the most recent pic are installed in the bottom of the upper fork tube and held in by a circlip. The rod that gets bolted into the bottom of the lower tube get dropped in from the top of the upper tube and passes through the pieces that have been the subject of this thread. The initial concern was the direction that castellated spacer was to face and when reassembling I realized the pics I had and the ones posted didn’t clearly show which end of the piston faced in which direction. After studying it a bit I realized that the angled end allows for the very bottom of the cylinder shaft (which has a sloped/angled piece) to nest into the piston when fully compressed.
Hope that explains what I was getting at. I’m pretty confident I’ve got it correct now.
As far as having removed them, yes you’re correct. It wasn’t entirely necessary. Unless of course you share an equal level of OCD to mine.
was compelled to be sure all was as clean and proper as it should be.

 

[thuban]

Thuban -
I’m pretty sure I’ve got it.
The pieces in the most recent pic are installed in the bottom of the upper fork tube and held in by a circlip. The rod that gets bolted into the bottom of the lower tube get dropped in from the top of the upper tube and passes through the pieces that have been the subject of this thread. The initial concern was the direction that castellated spacer was to face and when reassembling I realized the pics I had and the ones posted didn’t clearly show which end of the piston faced in which direction. After studying it a bit I realized that the angled end allows for the very bottom of the cylinder shaft (which has a sloped/angled piece) to nest into the piston when fully compressed.
Hope that explains what I was getting at. I’m pretty confident I’ve got it correct now.
As far as having removed them, yes you’re correct. It wasn’t entirely necessary. Unless of course you share an equal level of OCD to mine.
was compelled to be sure all was as clean and proper as it should be.

Repeat, yep, I think you have it. I took pix and I still had to think about it. I did take mine totally apart also. I had watched a you tube and it looked simple, just remove the bolt in the bottom. My bolt was TIGHT! When in did turn it was turning the cone piece, just spinning. So, it was the 11/16 socket "special Tool" and it was all down hill from there.
By the way, Welcome to the forum! There is hundreds and hundreds of years experience here. These guys are really a cut above when it comes to knowledge about the XS650. Good Luck
Thu

 

[5twins]

Yes, on most of these, that bottom bolt was installed with a combination of thread locker and sealer on the threads. Once you break it loose, it usually spins the whole damper rod with it unless you hold the damper rod some how. From one of the shop manuals .....

 

[REPETE]

Thanks All
Onwards!

pete