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

White Trash Bobber Resurection and Top end rebuild

Discussion in 'The Garage' started by lidirtrider, Jul 11, 2019 at 4:46 PM.

  1. lidirtrider

    lidirtrider XS650 Addict

    Well, after a VERY long hiatus I'm back to finally finishing this bastard. It was smoking like a James Bond smoke screen and shooting liquid oil out of the pipes so I know I got some top end issues. I pulled the motor out yesterday and today I gave it a good bath and took off some of the covers and smaller parts and bagged and labled everything. I'm gonna take my time and get this shit right. I only wanna do this one time. I've searched everywhere I can, and read far too many threads to remember so I think I have good idea of how to go about all of this. I'm sure I'm still gonna ask some questions, but hopefully not too many.

    I'll get some pics uploaded soon.
    Last edited: Jul 15, 2019 at 9:14 AM
  2. GLJ

    GLJ Ran through life like my hair was on fire 650 time Top Contributor

    lidirtrider likes this.
  3. lidirtrider

    lidirtrider XS650 Addict

    Yes saved it and read multiple times already. I'll be referring to it extensively.
    GLJ likes this.
  4. lidirtrider

    lidirtrider XS650 Addict

    Heres a few pics after I washed the engine a little, and pulled off all the tappet covers, cam covers, oil pipe, etc. This is gonna be a slow methodical dissaembly and rebuild. Carbs are going out to Old Skool Carbs tomorrow. I'm gonna start at the top and inspect, clean, measure, re inspect, maybe paint as needed, re inspect, and reassemble from the rocker box on down.

    IMG_5922.JPG IMG_5923.JPG IMG_5924.JPG IMG_5925.JPG IMG_5926.JPG IMG_5927.JPG IMG_5928.JPG IMG_5929.JPG IMG_5931.JPG IMG_5932.JPG IMG_5933.JPG
    Jim likes this.
  5. lidirtrider

    lidirtrider XS650 Addict

    Ok so first question. As you can see I have brass washers on all 8 engine studs. Can I reuse those, or should I get new ones when I order all the parts I need?
    Jim likes this.
  6. Jim

    Jim The thrill of victory and da agony of da feet. Top Contributor XS650.com Supporter

    Brass anneals the same as copper (comment #1 in the top end link above). Anneal 'em and reuse 'em.
    Tim Meaders, gggGary and lidirtrider like this.
  7. lidirtrider

    lidirtrider XS650 Addict

    Sweet. I thought that based on your utterly thorough guide. Just wanted to make sure. Thanks!
    Tim Meaders, gggGary and Jim like this.
  8. lidirtrider

    lidirtrider XS650 Addict

    I got the top end taken apart the other day. The first thing I noticed is that there were no dowels installed between the cylinder and the head, and none between the head and rocker cover. I'm guessiing that is, at least 1 of, the issues that would cause oil to get in the cylinders. It looked like the head gasket was a little misaligned too.

    So far it seems like I made some major errors when I originally assembled the top end. I'll post some pics soon. I took a lot as I was working and dont want to flood the thread with a lot of unneccesary photos.

    The good thing is now I get to order some more tools and instruments to measure and test everything.
    Last edited: Jul 14, 2019 at 3:31 PM
    Jim likes this.
  9. lidirtrider

    lidirtrider XS650 Addict

    Here are some pics from dissamebly on Friday. I can see some issues right away, and they only serve as strong lessons that I clearly did not do enough research before I had orinally assembled the engine. A little background on this project; I have another thread that shows a little bit of the initial build, then I fell off the planet for a while. The motor was orinally just the complete bottom end that looked like it was better used as bird's nest. We completely diassembled everything, had the crank rephased by Hugh, and had to buy every single component of the top end. Why not make it big bore? So Mikes 750 kit, PAMCO, etc, etc. So with that said, having to buy every part I could find, we missed a few, and thats on us.

    The first things I see are that, as I said above, it missing the dowels/sleeves between the head and cylinder, and between the head and rocker cover. I didnt even know that it needed those at the time of assembly. My fault. So without those dowels, it looks the head gasket, and possibly the head were a bit misaligned. You can see in some of the pics, that part of gasket looks chewed off near the cam tunnel. I guess we're lucky that misalignment didnt seriously damage anything. I can also see that the oil baffle is mising from the head. If I can find one I'll install it, but I've read here that it may not even be a critical component. Again, my fault for missing that to begin with.

    Looking into the cylinders, they still look super shiny. We did not hone/deglaze the cylinders before assembly, so again, I assume that led to the rings not seating and sealing and dumping oil in the chamber. Again, my fault. Didnt know I needed that on a brand new cylinder. Assumed, "it's brand new, should be perfect." WRONG! And you can also see how much oil is dripping down the cylinder walls.

    I'm not using my ignorance as an excuse, but hey, I didnt even know. Just glad I was able to learn from those mistakes, and caught them when I did. In addition to learning what parts go in the top end, I have read so much good info here on how to measure the cylinders, pistons and rings, and tolerances for such. I went ahead and ordered a bunch of new tools and materials so I can properly measure everything and do the work myself. I got so much stuff I need to expand my tool chest.

    I plan on disassembling the head and valves today, possibly remove the cylinder and pistons. I'm also contemplating disasembling the rockers too, mostly just so I can clean everything really well. Unless theres really no need to do anything up there.

    So enjoy the photos and please feel free to critique and point out anything I may not be seeing.

    Thanks all,

    I'm going to do my best to keep this up to date as best I can.

    No Dowels Bottom inner left, and top inner right.

    Gasket looks misaligned.


    No Oil Baffle


    Oil on cylinder walls


    No Cross Hatching on cylinder walls



    Last edited: Jul 15, 2019 at 9:18 AM
  10. lidirtrider

    lidirtrider XS650 Addict

    Not too much to report today. I thoroughly cleaned the rocker box cover inside and out, and put a light coat of assembly lube on the rockers and such. Got the head all disassembled, except for the valve guides, which were brand new, so no need to mess around with them. Everything is all bagged and labled according to where it was removed from. Got some packages from UPS with some new tools too. Got a set of Telescoping gauges so I can measure the cylinder, a nice new Dial indicator and some various chemicals, and wire wrap and stuff.

    Should be able to get the cylinder off and take the pistons and rings apart tomorrow. I know I'm going to have to hone/deglaze the cylinders. What size and type of hone does anyone recommend?
    Last edited: Jul 15, 2019 at 4:25 PM
  11. GLJ

    GLJ Ran through life like my hair was on fire 650 time Top Contributor

    INMHO I do not recommend honing the cylinders yourself. Also INMHO I would replace the rings. The up down pattern you see on the cylinder walls is also embedded in the face of the rings. Find a automotive machine shop that uses modern tooling and procedures. The days of running a ball hone through to knock the glaze off went away when moly ring came out. I have had 2 650 cylinders bored recently. Had them done at a automotive machine shop I helped out part time in the 90s. One of the things I did back then was bore and hone cylinders. Had a talk with the current owner. He worked there full time there when I was helping out. I asked him if things had changed since I worked there. He laughed. Said it was a lot different. Ring manufactures spec a lot different wall finish than I used to do. Even though you are dealing with a 40+ year old engine your pistons and rings are modern. Let us know how you make out checking your piston to cylinder clearance. Telescoping bore gauges are not something that are easy to be good at. Takes a lot of practice.

    Edit: Just my 2 cents.
    lidirtrider and Jim like this.
  12. Jim

    Jim The thrill of victory and da agony of da feet. Top Contributor XS650.com Supporter

    Or just a good teacher.... :rolleyes:

    lidirtrider likes this.
  13. GLJ

    GLJ Ran through life like my hair was on fire 650 time Top Contributor

    Jim sorry to disagree with you. Watching a video is not going to make you good at it. Takes a lot of practice comparing your results with some one else's that is good. The last cylinders I had bored Kory found 3 ten-thousands difference between them. In my best day I couldn't see that. And bored accordingly. Myself in my best day 3 tenths was past my limit. Maybe you have had enough practice and trust in your self, me I leave it to a professional.

    Edit: 3 tenths and then honing to that.
    lidirtrider likes this.
  14. Jim

    Jim The thrill of victory and da agony of da feet. Top Contributor XS650.com Supporter

    Well, having taught that method for the better part of 15 yrs.... I'll have to disagree with you. just about all my students took to like a duck to water. 15-20 min and they'd get consistent readings.
    lidirtrider likes this.
  15. GLJ

    GLJ Ran through life like my hair was on fire 650 time Top Contributor

    OK you win. I do think some things are best left to people that do it for a living.
    Jim and lidirtrider like this.
  16. lidirtrider

    lidirtrider XS650 Addict

    Thanks for the input fellas. I like the idea of learning and doing it all myself. The tools were inexpensive enough that I figured what the hell. I'll give it a shot and if I cant get consistant, repeatable measurements, I'll bring it to a shop. To me, there is no substitute for learning new skills, and acquiring new tool tools and equipment. After all, I'm sure this wont be the last 650, or motorcycle for that matter, that I ever work on.

    GLJ, since you pointed out the scoring on the cylinder wall, and said that it could also be embedded in the rings, I understand the possibility of new rings too. This engine has no more 10 minutes of running time. It smoked so badly I was afraid of doing any damage. Its only been fired up about a dozen times and for no longer than a minute at most. It usually stalled after 15-20 seconds because it was so oil fouled. And it was embarresing as hell to have a giant smoke screen cover the neighborhood. So with that, do you think that was long enough to do any major damage, or enough to replace the rings?
  17. GLJ

    GLJ Ran through life like my hair was on fire 650 time Top Contributor

    You're in this deep what the heck's a new set of rings. Piston to bore clearance, ring seating is the most important parts of a rebuild. Do you want to take that chance. A new set of rings can't compare to the time and expense of doing it over again. Myself I would not hesitate to spend the money.
    lidirtrider likes this.
  18. GLJ

    GLJ Ran through life like my hair was on fire 650 time Top Contributor

    Some may disagree with me. When I took the first 650 cylinders to Kory and had him check the wear I told him the min and the max. It took him a few minuets to check the sizes. When he got done I asked what I needed to do. He replied what to I want it to do "just run or be perfect" I got his jist. Ordered new pistons. As much as I enjoy working on engines I like them to run well and for a long time.

Share This Page