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Front Forks troubleshooting help.

Discussion in 'XJ Technical Chat' started by cds1984, Nov 29, 2020.

  1. cds1984

    cds1984 Active Member

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    Hi,
    I've recently refurbished my front forks, previously the wavey washers were in the wrong order so they basically sucked, with no dampening at all.

    I decided, while I was there to change to progressive springs also.

    Now the forks have good feel braking and general riding but when I lean over, at low speed, around corners(turning into an adjacent street) it almost feels like the front end is kinda chopping, chipping or something weird.

    Very unnerving!

    Hmmm...

    - new 10weight fork oil.
    - new seals.
    - new progressive springs to suit with a spacer that only sits level at the top of the forks when extended - so no extra pre-load.
    - air around 10psi.

    Any ideas would be appreciated.
    Thanks.
     
  2. FJ111200

    FJ111200 Active Member

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    What's it like with no air or less than 10psi? Could give that a whirl first.
     
  3. Yammaat

    Yammaat Active Member

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    you don't need air with prog. springs
     
  4. cds1984

    cds1984 Active Member

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    Ahhh, I'll dump the air and give it a whirl.
    Thanks.
     
  5. Yammaat

    Yammaat Active Member

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    Another possibillity could be your fronttire is cupped. And now you notice it due to the new springs.
     
  6. cds1984

    cds1984 Active Member

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    Front tire is nice and round still, I do like to try and be Wayne Gardner around those sweet slow corners. Knee down!
    But, I'll let you know if the air is the issue.
    Thanks again.
     
  7. Yammaat

    Yammaat Active Member

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    Sweet :D
     
  8. cds1984

    cds1984 Active Member

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    I dumped the air and it felt a bit better, but still funky.
    I suspect I have something going on that needs more attention.
    Going to pull the forks and check the triple tree and front wheel bearings and while I'm about it pull the swingarm and check those bearings and wheel bearings.
    Something ain't right!

    Thanks for the help, I'll let you know what I come up with.
     
  9. FJ111200

    FJ111200 Active Member

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    Good idea mate. Worn swingarm or rear wheel bearings can affect the handling up front. Don't skimp by just checking the front.
     
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  10. Yammaat

    Yammaat Active Member

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    Steeringhead bearings.
     
  11. Franz

    Franz Well-Known Member

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    Is there any side play in the swing arm, or movement in triple tree bearings pulling and pushing on the fork legs. Basic checks l know you have probably tried these. Check wheel bearings too by trying to move the wheel top and bottom.

    How did the bike handle before you worked on the forks? If it was fine chances are the problem is fork related.
     
    Last edited: Dec 4, 2020
  12. cds1984

    cds1984 Active Member

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    Hi Franz,
    I have 2 bikes, basically the same but both built up over the years to what they are now.

    The big thing is, I've been struggling with ignition problems with this bike so long that just being able to go in a straight line was a win... now that the ignition is working well...
    ack!
    At any rate, I've switched to my other bike and will pull this sucker down and report my findings.
     
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  13. Yammaat

    Yammaat Active Member

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    Good to read you solved the ignition issue(s). What was the culprit?
     
  14. cds1984

    cds1984 Active Member

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    Replaced with the New TCI ignition module, new plug caps, xjr1300 coils pretty much came down to the TCI after all the pain and suffering.
    Ahh good times.
     
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  15. cds1984

    cds1984 Active Member

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    Ordering a 22mm 1.5 pitch tap to clean out the stub axle thread tomorrow.
    It has always been super tight, like a cross threaded issue, so hopefully if I can get it sorted then my swingarm will behave in future.
    Not cheap though! $136 ouch... then again if it helps I'll be happy.
     
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  16. k-moe

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

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    The original fork springs were progressively wound, so yes you do want that adjustable air spring to be in play.

    @cds1984 10 weight fork oil is a bit thin for the XJ750 (even though that's what specified). Most of us end up running 15 weight.

    Keep in mind fellas, all the fork and shock specs and recomended adjustments were based on a rider who is likely much lighter than any of us are (apologies if you happen to weigh 135 pounds).
     
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  17. Yammaat

    Yammaat Active Member

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    Well.. I guess that the original springs could be a bit weaker than the new ones when installed. The originals where more suited for a comfy ride so less stiff.
    In Europa the pace on bikes seems to be a bit more harsh and roads aren't always that good when leaving the mainroads where you can use the throttle ánd brakes/suspension.
    The newer prog. springs are much stiffer than the original ones so.. no air needed. If one prefers to ride with air, fine with me :cool:
    Forkoils; sofar to my knowledge is there no standard regarding the viscocity of the fluid. A manufacturer grades it's own product.
    For me synthetic 5-30 motoroil does the trick with a certain amount of air in the chamber.

    My SecaRat has to haul at least 75 kg. :rolleyes:
     
    Last edited: Dec 17, 2020
  18. cds1984

    cds1984 Active Member

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    Ahh, new oil on its way too then.
    Thanks.
     
  19. cds1984

    cds1984 Active Member

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    The tap sure did clean up the threads but I'm also changing from a fixed stub on one side to 2 adjustable stubs so I have more control (I have a lot of spare parts).
    Stripped everything down, this sucker will be spot on when I'm done. (Well I hope).

    On to the forks after this is finished.
    PXL_20210124_094635893.MP.jpg PXL_20210124_094646089.MP.jpg PXL_20210124_094717384.MP.jpg PXL_20210124_094626398.MP.jpg PXL_20210124_094618259.MP.jpg
     
  20. cds1984

    cds1984 Active Member

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    No pictures but, finally put it all back together and centred the swingarm with the 2 smooth as hell adjustable stubs, checked the headset for slack(there was none) and changed the fork oil to 20W instead of 10W and put the prescribed amount of air back in.
    Oh put new tyres on also, while I was at it.
    Rides like a charm now, so, it was one of those bits!

    Thanks again.
     
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