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Holy Grail of XS400 Big Bore Pistons

Discussion in 'The Garage' started by aaronxs400, Dec 24, 2012.

Tags:
  1. Wolfe_11B

    Wolfe_11B XS400 Guru Top Contributor

    Yes, taking into account the 1mm difference on the rods
     
  2. xschris

    xschris XS400 Guru Top Contributor

    Will be watching:)
     
  3. Robsteeler66

    Robsteeler66 XS400 Addict

    Are you talking standard size or bored out? I'm interested to see how this turns out.
     
  4. Wolfe_11B

    Wolfe_11B XS400 Guru Top Contributor

    69-73, so whatever your heart desires :)

    I'm very hesitant of the valve reliefs though.... I think they may be too small
     
  5. Any updates yet? I'm very interested in this topic.
     
  6. salisride

    salisride XS400 Addict

    Hey man I think the fj1200 and 1300 rod (36y) rod is the same dimensions as the xjr rod (5EA). the fj rods are a littler weaker and heavier, but They'll still be plenty for our motors and can be found more easily.
     
  7. XS400Cup

    XS400Cup XS400 Member

    Yes, that's right.
     

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  8. Wolfe_11B

    Wolfe_11B XS400 Guru Top Contributor

    I ended up getting a FJ rod off of ebay but couldn't do anything with it. Seller failed to disclose that it was bent. My motor is back together so I can ride this bike at least once this year. Over the winter I'll try to get a junk motor to test around with.
     
  9. Campbell45

    Campbell45 Penny Pincher

    To update to this. Crazypj mentioned on another thread that xs650 liners and gsxr1100 78mm pistons would be able to fit. If thats true then we would have a 501cc engine. But later I believe he went on to use gs500 liners and pistons. Gs500 uses an 18mm wrist pin with a 26mm crown height.

    Im hunting as well..
     
  10. XS400Cup

    XS400Cup XS400 Member

    I use modified GS500E liners for 488ccm.
     

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  11. drewpy

    drewpy Excess twin Top Contributor

    what pistons did you use?

    were they the same con rods?
     
  12. Campbell45

    Campbell45 Penny Pincher

    And when you say modified what needed to be done?
     
  13. Wolfe_11B

    Wolfe_11B XS400 Guru Top Contributor

    I decided to just buy sanglas pistons for mine, no mods needed and a good price. They aren't big bore, but do add compression with a raised dome. Coming from Spain though, so won't have them for a week or two.
     
  14. XS400Cup

    XS400Cup XS400 Member

    XJR1300 rods and XJR1200 pistons (77mm)

    The GS500E liners were modified as shown in the attached image.
     

    Attached Files:

  15. Campbell45

    Campbell45 Penny Pincher

    arnt the xjr1200 pistons the same as fj1200?
     
  16. XS400Cup

    XS400Cup XS400 Member

    different part numbers:
    1TX-11631-00-A0 for FJ1200
    4PU-11631-00-A0 for XJR1200

    but i dont know what the differences are, because the XJR pistons can be used in the FJ.
     
  17. drewpy

    drewpy Excess twin Top Contributor

    I need a quote for cylinder liners but need more measurments.

    Can anyone give me the length of the liners please?
     
  18. Myke Nytemare

    Myke Nytemare XS400 Enthusiast

    Definitely interested in knowing more, like which sleeves and rods were used... Parts numbers?
     
  19. Wolfe_11B

    Wolfe_11B XS400 Guru Top Contributor

    It's all there in the post you quoted.
    The cheapest I found the rods were for 113 a piece. 5EA-11650 are the rods.
    The liners he used were GS500E, machined to fit the XS jugs. There are many others you can use, since they are getting machined anyway. All depends on which pistons you are going with. Keep in mind, It's not cheap at all to have sleeves and pistons modified at a machine shop.
     

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