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xj650 maxim master cylinder for dual disk brakes

Discussion in 'XJ Technical Chat' started by MaximusXJ650, May 23, 2019.

  1. MaximusXJ650

    MaximusXJ650 Member

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    I have an xj650 maxim single disc setup currently and I've recently come into some front forks for the dual disk set up - minus the master cylinder.

    I believe these are off of an xj650 seca

    Will my original master cylinder be compatible with the dual disc set up or do I need to invest in a bigger master cylinder?

    Thanks in advance
     
  2. Chitwood

    Chitwood Well-Known Member

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    No it will not. Depending on what handlebars you are running will partly determine what MC you need. Look up the specs for a MC off a dual disk DJ (650 or 750 should be the same) and go from there. You will likely need one with a bigger bore, whether or not you need an angled one will depend on your bars
     
  3. jayrodoh

    jayrodoh YimYam Premium Member

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    If you are changing to flatter bars, the Seca 650 Turbo MC is a perfect match for your application. The original MC from your Maxim will be too small of a bore and the lever will travel far and be spongy.
     
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  4. MaximusXJ650

    MaximusXJ650 Member

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    I was aiming to keep the bars the same for now
     
  5. jayrodoh

    jayrodoh YimYam Premium Member

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    One from a 750 Maxim should be perfect then. 16mm bore and maintains the angle for the "buckhorn" bars. Some of them had a low fluid switch in it, you can just plug the hole or tuck the wiring into the headlight.
     
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  6. MaximusXJ650

    MaximusXJ650 Member

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    Thank you Jayrodoh, you've been a great help.

    One last thing if you could, I've found a 750 maxim master cylinder (used) for £42. If you see the pictures below, is there anything else I need to obtain? I have the forks and the calipers with the 2 into 1 adapters on them. I think I may need to get the brake hose that runs from the cylinder and connects to the 2 caliper adapter (also pictured)
    Screenshot_20190524-003845_eBay.jpg Screenshot_20190524-003849_eBay.jpg Screenshot_20190524-003844_eBay.jpg Screenshot_20190524-003457_eBay.jpg Screenshot_20190524-003459_eBay.jpg Screenshot_20190524-003505_eBay.jpg
     
  7. XJ550H

    XJ550H Well-Known Member Premium Member

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  8. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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    One from an '83 Maxim 750, or '84 Maxim 700 would be the best fit. The buckhorn bars are the same as on your 650.
    The earlier Maxim 750 uses different bars and the angle might not be correct.
     
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  9. MaximusXJ650

    MaximusXJ650 Member

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    Thanks all

    I've asked the seller for the year of bike the advertised master cylinder came from.

    He has it advertised as an MC that will fit 82 and 83 xj750 maxim
     
  10. XJ550H

    XJ550H Well-Known Member Premium Member

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    the 82 MC would have a float part 6 and wire port the 83 did not.

    82 750 maxim is kind of a hybrid seca/maxim.
     
  11. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    Both the '82 and '83 XJ750 Maxim master cylinders would be correct for a situation using the curvy "roto-tiller" handlebars, since these require a m/c that has a "tilted" reservoir (the tilt on the m/c mounting results in a reservoir that is "level" (horizontally) when mounted on the curvy bars). The only difference between the '82 and '83 m/c's is the fluid level sensor system on the '82 models, and you can just not use it (or, can't use it, as there is no place to hook up the wires nor a gauge to monitor it with on an XJ650 Maxim).
     
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  12. XJ550H

    XJ550H Well-Known Member Premium Member

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    speaking of roto-tillers :) I have to do my garden tomorrow.
     
  13. MaximusXJ650

    MaximusXJ650 Member

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    Ok thanks guy.

    So going back to my previous question, looking at the pictures is there going to be anything else I would need other than the MC pictured and the cable feed from MC to caliper adapter?
     
  14. MaximusXJ650

    MaximusXJ650 Member

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    Chacal are the cables in this picture for the switch you mentioned? If so can I just cut them off or hide them/tuck them away?

    Screenshot_20190524-003505_eBay.jpg
     
  15. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    Maximus, yes tuck them away. But note that one set of wires is for the front brake light switch (green and brown wires) and of course you'll keep those/don't cut them! The other set.....white/black stripe and black........that enter the bottom of the reservoir can be cut, or a better idea is to just wrap them up and place them out of the way.
     
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  16. MaximusXJ650

    MaximusXJ650 Member

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    Thanks again, much appreciated!
     
  17. MaximusXJ650

    MaximusXJ650 Member

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    Anyone have any idea on how to remove the brake light switch wires from the reservoir? I need the the whole to come out including piston

    View attachment 35491
     
  18. MaximusXJ650

    MaximusXJ650 Member

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    Scrap that I figured it out!
     
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