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A bit of History "Pops" Yoshimira

Discussion in 'The Lounge' started by gggGary, Nov 6, 2013.

  1. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    An interesting read, starts out discussing a Yoshimura prepped race GS1000 then gets into the rather amazing early life of Pops. An interesting tidbit in the GS tech part may have relevance for the XS650. Bonus points if you guess what I mean!

    http://slcelectronics.com/GS1000_Build/Yoshimura-specs.pdf
     
  2. xjwmx

    xjwmx XS650 Guru Top Contributor

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    Let'see...you want to grind your cam chain adjuster so it only contacts the rollers...
     
  3. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Nice thought, but not what I was thinking about!
     
  4. xjwmx

    xjwmx XS650 Guru Top Contributor

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    Not sure what else it could be unless you're dreaming of 135 hp. Can't be that...
     
  5. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Thanx for the trip down memory lane. We used to sell Pop's stuff, including his 4-into-1s. I'll never forget watching him hand grinding racing Honda 70 cams. Always wondered what happened to him after 1975.

    On your 'relevance to the XS650', my best guess is the polishing of the camchain link edges, something that's been on my 'wanna try' list...
     
  6. 650Skull

    650Skull Dinosaur Lives Top Contributor

    Something like this. XSjohn pic, he was doing it to his cam chains
     

    Attached Files:

  7. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Honestly when I posted I thought sure too many would get it, but not yet.
    Hint; it's not cam chain related.
     
  8. peanut

    peanut XS650 enthusiast & inveterate tinkerer XS650.com Supporter Top Contributor

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    lots of neat ideas there .

    Haven't finished reading the article yet but my guess would be
    Steel clutch carrier instead of aluminium ? to prevent plate tangs cutting into the ali carrier teeth and thereby reduce clutch drag ?:)

    Undercut gear dogs for more positive engagement is a neat mod too

    How about the folded clutch plate tangs ??......are we getting warm


    Does the winner get a trip to the Seychelles ?:laugh:
     
    Last edited: Nov 7, 2013
  9. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Maybe but it won't be you. Keep trying guys. The mod is not too far off in an odd corner, I think it affects a (more than always realized) common XS650 issue and a rather unique way to deal with it! Bonus it's something that could be (should be?) done by the serious home builder.
     
  10. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Well, I was trying to remember the name of that 'heat conducting' paint used in the `70s. The article talks about aluminum-oxide blasting and Kal-Gard coating. I believe that may have been the paint I heard about, remembered something about military applications...
     
  11. peanut

    peanut XS650 enthusiast & inveterate tinkerer XS650.com Supporter Top Contributor

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    I saw that bit but my thinking was as a DIY builder I would install an oil cooler first which would be much more efficient in cooling the engine.

    I guess it has to be something that would be relevant to all of us because if it was a racing mod it probably wouldn't be very relevant

    What are the most common XS650 issues that effect us all ? clutch, gearing, handling and for part of the World over heating perhaps. what else ?
     
  12. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

  13. xjwmx

    xjwmx XS650 Guru Top Contributor

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  14. jd750ace

    jd750ace Front Toward Enemy

    Without having the time to read it all the way through (leaving to go back to Texas for good tomorrow), I'm going to guess lateral bracing above the swingarm pivot.
     
  15. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    No joy yet.

    OK big hint crankshaft.
    Maybe it's me in the wilderness? (again)
     
  16. xjwmx

    xjwmx XS650 Guru Top Contributor

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    Ok, got it now. He beefs up the crank. You bent a crank. We had to dig hard to discover it was actually a motor that you'd 750'ed.
     
  17. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Yes the use of some sort of anerobic glue when pressing the crank together. I have a crank that got loose enough to wobble, I haven't opened it yet but I would bet the RH con rod pin is where the problem lies, it's not a 750 it's a stone stock 650 with about 20K miles. I put about the last 1000 on it without issue or serious flogging. I also have a 750 kitted motor that has developed a bottom end "whir" I'm guessing a pin is moving in that one too. Several others have heard that dreaded bottom end whir which I think is either bearings being heavily loaded sideways or the crank starting to mill the crankcase.
     
  18. xjwmx

    xjwmx XS650 Guru Top Contributor

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    I think I remember a video of yours where the crank was obviously wobbling. I was following those 'wirring' threads too because mine does it, but only if the temp is below about 40 and only for a few minutes until it warms up. And not really loud. I told a mechanic I know who's worked on these full time all his life and he said it can come from a crank bearing with a pit, But he said it wasn't that in my case because it would do it all the time. It's been two or three years and it's not changing, so I'm not very concerned.

    The same guy, once I told him had to replace the diode inside one of the relays and I started to tell him what the symptoms had been, and he told me what they had been before I could! That amazed me. Especially now, since I can't even remember for sure what the symptoms were myself.
     
  19. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    It should be easy enough to drop the sump and measure between the flywheels on both sides....... want to do that on several cranks I have to see if it will allow a simple oh crap the pin is working loose diagnosis. Yamaha's race guide talks about the pins, says if less than 20 tons is needed to press the pins in they are too sloppy for race use...
     
  20. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    That glue could be interesting stuff. The way I read it, implied it had to be done at the factory, presumably with special alignment fixtures to avoid the whacking necessary to align it...
     

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