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Thread: 85 ATC250R front shocks question

  1. #1
    Join Date
    Jun 2004
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    85 ATC250R front shocks question

    I noticed my front forks have no air in them..do i need to put some in them? and if i do how do i go about doing it? Thanks

  2. #2
    timex69 is offline Just Too Addicted Arm chair racerJust too addicted
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    i dont think its air they put it in..its some sort of gas. You just take it to the dealer and theyll recharge it for you.

    alex

  3. #3
    Join Date
    Jun 2003
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    englishtown NJ
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    don't put air or anything in them, it will cause you seals to blow out. I don't understand why the fitting is on there, probably to allow you to release pressure before you are gonna take them apart..

  4. #4
    Join Date
    Jun 2004
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    Mississippi
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    The valve is for air. It has a max of 1psi. DO NOT use compressed air. You have to use a hand pump. From my experience it just makes the ride to stiff for me. Someone like deathman may benifit from it with his kller jumps.
    2000 Banshee: Modded out!!!
    1985 ATC 250R: Bone stock but not for long.
    1984 ATC 185S: Modded out!!
    1979 ATC 110: Stock execept fork extentions
    1984 ATC 110: Same as above


  5. #5
    Join Date
    Feb 2004
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    Actually, the air nozzle is to let the air out of the forks. Like when the temp goes up or down, or in different elevations, or any atmospheric conditions change. The air inside should be equal to the air outside. This is found in the shop manuals for the 200x, 350x and 250r.
    RIP - Yamahondaman!! You will never be forgotten!
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  6. #6
    Join Date
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    Default is 0 psi. You have to make sure the front is lifted so there is no weight on the forks when you bleed it out to static pressure, otherwise your forks will be under vacuum. You can put a few psi of air in them if needed, as a band-aid if your springs are too light, but its not a fix. Anything over 8 or 9 lbs, and your forks wont even compress.

  7. #7
    Join Date
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    Tim Sr, won't 8 or 9 PSI blow out the seals??
    RIP - Yamahondaman!! You will never be forgotten!
    RIP - Sam Brehm!! Gone but NEVER forgotten!
    RIP - Sandpuppi101 - You will live on in my mind - I miss you friend!

  8. #8
    Join Date
    Jun 2004
    Location
    Mississippi
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    I got my info out of a clymer manual also. It is an air assist incase you win a lot of races and get a twinky sponsorship. lol
    2000 Banshee: Modded out!!!
    1985 ATC 250R: Bone stock but not for long.
    1984 ATC 185S: Modded out!!
    1979 ATC 110: Stock execept fork extentions
    1984 ATC 110: Same as above


  9. #9
    Join Date
    Feb 2004
    Location
    Tionesta, PA
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    My 200x front forks have mad sag because of weak springs, but I was told if I put any air in them it would blow out my fork seals. Has anyone here actually used a hand pump to insert air into forks. If so It would help my cause big time.
    RIP - Yamahondaman!! You will never be forgotten!
    RIP - Sam Brehm!! Gone but NEVER forgotten!
    RIP - Sandpuppi101 - You will live on in my mind - I miss you friend!

  10. #10
    Join Date
    Jun 2004
    Location
    Mississippi
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    83
    I did it on my 85 R. My forks are in great shape and it just made them to stiff for me. Like I said though. Use a hand pump. Compressed air will immediatly blow out the seals. 1-1.5psi is acceptable but no more than that. I rode mine for about a week with 1lbs in it and never blew a seal.
    2000 Banshee: Modded out!!!
    1985 ATC 250R: Bone stock but not for long.
    1984 ATC 185S: Modded out!!
    1979 ATC 110: Stock execept fork extentions
    1984 ATC 110: Same as above


  11. #11
    Join Date
    Sep 2002
    Location
    Rittman, Ohio
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    Quote Originally Posted by atctim
    Tim Sr, won't 8 or 9 PSI blow out the seals??
    Your getting more pressure than that when you simply compress the forks. There is very little volume in there (after oil), and when you compress the forks you eliminate most of its so you are compressing air in a fraction of its space. Thats why they are very hard to pressurize or measure right. One tap with an air hose and they are overinflated. Two hits with a pressure guage and they are deflated. Before I got my progressive springs I took my 12v low volume air pump and would hit each one with that for a second or two until it "felt right" for racing motocross, because I knew I would bottom out on the big stadium jumps. My best estimation and measurements, I was putting in about 7-8 lbs. I have an 85 TriZ, and anyone who has seen it knows its obviously been ridden A LOT. I still have the original OEM factory fork seals in it! Needless to say Im also a strong opponent of changing fork seals just for the heck of it, if they dont leak. The biggest culprit in blowing fork seals is too much fork oil. Oil doesnt compress!

    For your problem of sag due to weak springs, you can fix that by preloading them with a couple of PVC spacers, or you can get progressive springs from Dennis Kirk for about $75.

  12. #12
    Join Date
    Dec 2002
    Location
    Kansas
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    I have put PVC spacers in my front forks. I think that is one of the best mods I have done to my R. I put 1 inch of spacer in it.
    I had the RIGHT to remain silent, I didn't have the ability!

  13. #13
    250rAL is offline Just Too Addicted Arm chair racerJust too addicted
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    I've got 1/2 inch spacers in mine. Another mod that helps is to weld shut one of the two small oil return holes in the damper rod. This slows down the rebound and keeps the front end from bouncing up after big jumps.
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