1. Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

Slightly altered 83 XJ750 Maxim

Discussion in 'XJ Modifications' started by PavelK313, Jan 29, 2019.

  1. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    So XJ550H weights more than my bike. Lol
     
    XJ550H likes this.
  2. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    Just a random picture that I thought looked cool. :)


    IMG_2461.jpg
     
    sybe and k-moe like this.
  3. MattiThundrrr

    MattiThundrrr Not a guru

    Messages:
    3,690
    Likes Received:
    1,665
    Trophy Points:
    113
    Location:
    America's friendly hat
    Well, I think it looks kinda cool too!
     
    PavelK313 likes this.
  4. sybe

    sybe Active Member

    Messages:
    576
    Likes Received:
    138
    Trophy Points:
    43
    Location:
    NYC - Brooklyn
    Looks slick. How does she ride?
     
  5. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    Like a modern day sport bike. More specifically like a 2006 R1 with half the power. Lol
     
  6. sybe

    sybe Active Member

    Messages:
    576
    Likes Received:
    138
    Trophy Points:
    43
    Location:
    NYC - Brooklyn
    i would love to do this, but i dont think i would be able to weld everything on straight. Something would be slightly off.
     
  7. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    Bled front brakes today to change the fluid and went out for a quick ride. At first brakes felt great so I decided to see how well they’ll do their job in emergency situation and squeezed lever much harder than usual to the point of rear wheel started leaving the ground and rear brake locked up. I can to a stop and noticed my right brake caliper is covered in fluid, initial though was “oh got, I am an idiot and didn’t tighten bleeder screw”, a second later I realize that my fork, engine and as I look up my tank is covered in fluid. At that moment I realized that it wasn’t brake fluid but instead it was gas splashing out of the tank!

    So now I am at wow as I am not sure how to solve this problem. Gas tank cap seal appears to be in good condition with no visible cracks, spring that pushes seal down also appears to be in good functional condition.

    Any suggestions on what to do? Perhaps spring got too soft over the years?
     
  8. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    there is a vent in the cap plus 2 orings
    Your Gas Cap and You

    best suggestion is don't stand the bike up on front wheel use more back brake less front.;)

    you could drop a disc and caliper making the bike lighter ;)


    could be the springs holding the seal down
     
  9. sybe

    sybe Active Member

    Messages:
    576
    Likes Received:
    138
    Trophy Points:
    43
    Location:
    NYC - Brooklyn
    Two thoughts, is the bike perched too forward and front heavy with the fork swap and mono shock? Also sounds like you might need new gas cap seals. Maybe try re positioning it to see if you can get a better seal?
     
  10. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    It’s rear bias. 220 lbs rear, 200 lbs front, but I am not sure how myself and my riding position effects that.

    Not sure what stock Maxims weight distribution is.
     
  11. sybe

    sybe Active Member

    Messages:
    576
    Likes Received:
    138
    Trophy Points:
    43
    Location:
    NYC - Brooklyn
    I will be working on my bike this weekend, so i can take measurements of how high my rear frame hoop is off the ground and compare it to yours. From pictures it looks like you might have welded in the seats frame rails at a higher pitch. We have the same setup except i still have two rear shocks and 2013 r6 forks. You might need to get stiffer springs on the front forks to prevent fork dive and minimize weight distribution. When my bike was stock i never had the rear tire pick up during hard braking.

    How fast were you going?
     
    Last edited: May 21, 2019
  12. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    I wasn’t looking at the speedo, I would guess maybe 35-ish?
    I know stock maxim never did it that’s because front brakes sucked for such heavy bike.

    Sounds like you got an awesome project yourself! Initially I also wanted to go with R6 front end, but after weighing in pros and cons of R6 VS R1 I decided to go with R1 Front. My monoshock conversion was also dictated by cool factor, looks, performance and price.

    What tank did you go with on your bike?
     
    Last edited: May 21, 2019
  13. 50gary

    50gary Active Member

    Messages:
    343
    Likes Received:
    128
    Trophy Points:
    43
    Location:
    Saginaw, Mi. USA
    It's called a "stoppie" stunt guys do that on purpose, ride the front wheel with the rear high in the air. I think the nature of the increasing the progressive lever pressure is the cause? At least you didn't lock up the front, that's usually a crash. You have 52% rear weight bias probably typical for these bikes, I'm hoping to get 50/50 with out rider but that's only a goal at this point. I may have mentioned the front springs, I have Race Tech .9kgm in my R1 forks but your bike is very light compared to regular XJs. I hardly ever use the rear brake. Maybe the gas leaked out only because of the stoppie.
    Cheers, 50gary
     
  14. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    I don’t think my fork is an issue. My deciding factor for going with R1 suspension and trying to save as much weight as possible because I was trying to avoid changing springs since my bike and R1 weight about the same +/- few pounds. I do realize that gas leaked out because of stoppie, but I still would expect for gas lid to stay sealed.

    I ordered new gas door/cap yesterday. Will replace it once it comes in and report back.
     
    Uxbridge Brule likes this.
  15. sybe

    sybe Active Member

    Messages:
    576
    Likes Received:
    138
    Trophy Points:
    43
    Location:
    NYC - Brooklyn
    I don't think its your forks either, I am actually concerned that the adjustments made to the rear changed the center of gravity on the bike, making it easier for the back tire to lift up. Easy way to solve it is to date a fat chick and take her with you on rides.
     
    XJ75082 likes this.
  16. sybe

    sybe Active Member

    Messages:
    576
    Likes Received:
    138
    Trophy Points:
    43
    Location:
    NYC - Brooklyn
    I have a 650 seca tank on mine. It was all "done" then I got tired of the front end. also have been trying to find a solid solution for a swingarm swap for rear disc brakes and 17in rim upgrade.

    cognito is the only drum to disc available, but that comes with it's own headaches and crazy $$$.
     
  17. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    There are two issues when it comes to riding with fat chicks...

    1. I am married to a skinny chick
    2. My bike is a single seater :)
     
    Chitwood likes this.
  18. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,854
    Trophy Points:
    113
    Location:
    Great North Woods
    could have .just been the weight of the gas pushing forward compressed the springs and sloshed out
     
  19. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    That’s a definite possibility. It seems that vintage technologies weren’t designed for a lot of things.
    I never had that issue when my bike was stock with old suspension and crappy brakes.
     
  20. PavelK313

    PavelK313 Active Member

    Messages:
    205
    Likes Received:
    99
    Trophy Points:
    28
    Location:
    Fairfield CA
    Since my XJ is back on the road, I ended up selling my KLX250SF SuperMoto today.
    I really want to take XJ apart to refinish everything, but I also down want any down time not riding the bike. So more than likely refinishing will start closer to December or whenever the rain season starts.
     

Share This Page