1. Dismiss Notice
  2. Hey Facebook people... We've created a group for XS650.com members to connect. Check it out!
    Dismiss Notice

Mailman’s XS2 a full on restoration

Discussion in 'The Garage' started by Mailman, Mar 1, 2018.

  1. Jim

    Jim Beyond the edge is the unknown. Here be Dragons XS650.com Supporter Top Contributor

    Here's something else that might be worth trying if you have a leaky seal....
    Yamaha used both a gasket and an o-ring on the housings. Considering all the fastener holes are blind holes, it's a somewhat unusual arrangement. Normally on a setup such as this, you'd use a gasket or an o-ring... but not both. If you were to remove the gasket and just use the o-ring, this would move the seal lip in by the thickness of the gasket. That ain't much... but it might just be enough to get it off the worn part of the cam and onto a cleaner sealing surface. Considering it won't cost anything... might be worth a shot. :shrug:
    EDIT: You would first need to measure the flange on the housings and make sure there's enough room from the face to the cam bearing so you're not side loading the bearing (not pushing against the outer race).
     
    Last edited: Apr 13, 2020
    gggGary, GLJ, Mailman and 1 other person like this.
  2. Rasputin

    Rasputin XS650 Addict XS650.com Supporter Top Contributor

    Even the oil dribble is clean.
     
    2XSive, GLJ, Mailman and 2 others like this.
  3. Mailman

    Mailman Hardly a Guru Top Contributor

    :laughing: Well.........you know....:shrug:
     
    Rasputin, 2XSive, GLJ and 1 other person like this.
  4. 2XSive

    2XSive At least one screw loose behind the handle bars XS650.com Supporter Top Contributor

    345
    1,411
    143
    Michigan
    That's what my earlier post #3248 was about, Jim. I tried this already on the side that is leaking and it didn't help. It may work for others depending on the condition of the end of the cam and how finished the surface is. No amount of polishing seemed to help on mine. Seriously considering the speedi sleeve approach suggested by Ozboy.
     
    gggGary likes this.
  5. Jim

    Jim Beyond the edge is the unknown. Here be Dragons XS650.com Supporter Top Contributor

    Doh... yeah, guess I read it and didn't register for some reason... oops. :doh:

    Been looking all morning for that size sleeve. No joy so far.
     
    gggGary likes this.
  6. 2XSive

    2XSive At least one screw loose behind the handle bars XS650.com Supporter Top Contributor

    345
    1,411
    143
    Michigan
    I see Timken also makes SS sleeves called Redi-sleeve. Might be another option. Researching myself.....
     
    Jim and gggGary like this.
  7. Mailman

    Mailman Hardly a Guru Top Contributor

    I am also intrigued by the speedi sleeve option. I think I found the right one. It says the seal surface width is 8mm.
    Is there room on the shaft for that? And another question. Should the shoulder of the speedi sleeve be removed after install. I’ve watched several install videos on YouTube, some leave it on , others peel it off. Any way you look at it , it’s not an inexpensive fix. Speedi sleeve plus new seal.
    DBD6C06E-B17B-4F71-8719-117DA2FD16A8.png
     
    GLJ and Jim like this.
  8. MaxPete

    MaxPete Lucille, Betty & Demi - I suggest but THEY decide. XS650.com Supporter Top Contributor

    I have been thinking about this camshaft seal leak issue that keeps coming up and a solution from back in my dark past when I was a hydraulics specialist has occurred to me. Most hydraulic motors and pumps (especially axial piston units) have a seal drain to relieve the main shaft seals from having to deal with full system pressure. The seal drain is just a little hole that vents oil back to the tank at atmospheric pressure to prevent it from leaking out of the machine.

    The oil inside the XS650 cylinder head is essentially at atmospheric pressure and so the only reason for it to leak is that the cam bearings in our XS650s must be "pumping" the oil at the camshaft seals. That pumping action must be building up a higher pressure on the inboard side of the seal and that contributes to this persistent leak problem which so many people seem to experience.

    I wonder if a small hole could be drilled between the outboard cam bearing and the camshaft seal that would allow oil to drain from behind the seal back into the main body of the cylinder head. The hole could be very small (1/16" dia. or so I'd say).

    The other way to go at it would be to simply make a little "trough" in the bottom of the pocket in which the cam seal and bearings are installed - starting just inboard of the seal and leading back to the interior of the cylinder head rocker cavity. Again, the trough could be very small - say 0.060" wide and 0.030" deep (around 1.5mm x 0.75mm or so). That would have no measurable effect on the structural support of the cam bearings but it might relieve the pressure of their pumping action.

    That would ensure that any oil pumped onto the inside face of the cam seal had somewhere to go at atmospheric pressure - other than through the seal into the LHS breaker points or RHS advancer covers from where it leaks out all over the outside of the engine - spoiling the pristine appearance of Mailman's bike.

    Anyhow - I haven't been inside one of these heads for a couple of years so this idea may be all-wet, but perhaps someone who has a cylinder head apart could take a look at it and see if such a seal drain might be feasible. If it didn't work, the hole or "trough" could simply be sealed up again with JB Weld and no harm done.

    A sketch of what I have in mind is attached as a .pdf and I also took a photo of it (see below).
    Cam_Seal_Oil-Drain - PRF_13-04-2020.jpg
     

    Attached Files:

    Last edited: Apr 13, 2020
    Scripto VU, arcticXS, GLJ and 3 others like this.
  9. YamadudeXS650C

    YamadudeXS650C Central New York XS650 XS650.com Supporter Top Contributor

    I like it, Peter !
    Quick, apply for a patent.....
     
    Jim and Mailman like this.
  10. Jim

    Jim Beyond the edge is the unknown. Here be Dragons XS650.com Supporter Top Contributor

    Ahhh... the ubiquitous "cavity drain." I suppose if someone had an engine apart, it wouldn't hurt anything to drill 'em. I just don't see how a roller bearing could be pumping that much oil (or oil pressure) in there. A typical garloc seal such as these are regularly used to hold back upwards of a hundred psi.
     
    MaxPete likes this.
  11. MaxPete

    MaxPete Lucille, Betty & Demi - I suggest but THEY decide. XS650.com Supporter Top Contributor

    Naw - got some already and have never made a penny on them. I would however like to see this tried out.

    Pete
     
    Jim likes this.
  12. MaxPete

    MaxPete Lucille, Betty & Demi - I suggest but THEY decide. XS650.com Supporter Top Contributor

    True Jim - but the point is that those camshaft seals are about the only thing on these engines that persistently leak (as long as the output sprocket nut is tight) - and so SOMETHING is promoting that leak and all I can think of is the pumping action of the double set of ball bearings.

    Maybe the fit of the camshaft on the seals is wrong - or maybe the surface finish is poor......
     
    Jim likes this.
  13. Jim

    Jim Beyond the edge is the unknown. Here be Dragons XS650.com Supporter Top Contributor

    Yeah, that's not cheap. My 2 24mm seals were 10 bucks to my door. Think I'll try them first.
     
    2XSive and MaxPete like this.
  14. Paul Sutton

    Paul Sutton Still Looking Good Top Contributor

  15. Mailman

    Mailman Hardly a Guru Top Contributor

    Yeah, the easiest and most sensible solution would be to try a progressive approach. I’ll probably try a new seal first.

    That’s an interesting approach Paul. Forum member Willis ( Rob ) , has generously offered me a used one he had, so I’m gonna give that a go.
     
  16. Kentg

    Kentg XS650 Member

    Does the shaft unscrew (left or righthand threads) to enable removing the chrome outer cover?
     
  17. Mailman

    Mailman Hardly a Guru Top Contributor

    The short answer is , left hand. Turn right to unscrew.
     
    Paul Sutton likes this.
  18. arcticXS

    arcticXS XS650 Guru Top Contributor

    Pete,
    It is my understanding that you have been working for the automotive industry as well. I do know that some oem engine crankshaft seals have some kind of "oil pumping grooves", which are made for that engines specific direction of rotation. I am pretty sure Volvo Penta marine engines have this type of seal at the drive end of the crankshaft, and that fitting a generic seal mostly leads to oil leaks. Has anyone investigated this? OEM Yamaha vs generic seals? Obviously, the camshaft would require one seal for clockwise, and one for counterclockwise rotation. Just a thought anyway.
     
    YamadudeXS650C and MaxPete like this.
  19. Mailman

    Mailman Hardly a Guru Top Contributor

    I have a couple rotation specific cam seals on hand right now, but not a matching set of right and left. They both are for the same direction.

    A2E669C8-84F0-4AF7-AA19-DE77F0013F9A.jpeg
     
    GLJ, MaxPete and arcticXS like this.
  20. arcticXS

    arcticXS XS650 Guru Top Contributor

    It would be interesting to see how those worked out. Unfortunately it looks like they are correct for the RH/ ATU side, and would increase any oil leak on the ignition side. Are those OEM Yamaha?
     

Share This Page