1969 AT1 mx

Discussion in 'Some Assembly Required' started by slidewayes, Jun 17, 2018.

  1. slidewayes

    slidewayes slidewayes

    Joined:
    Nov 27, 2010
    Oddometer:
    836
    Location:
    HESPERIA CA
    My father was a racer in the 50's and 60's mainly Dirt track and road racing on BSA's and later a Yamaha TR3 late 60's he hung it up and bought some dirt-bikes for himself and his sons A Husky 400 and two Yamaha 125 AT1 mx Moto Cross was starting to grow and we jumped in Racing C.M.C races in So Cal Carlsbad - Saddelback- Indian Dunes This bike earned my brother a expert ranking in 1971 #39 and my self a expert rank in 1973 as # 91 ,This is what is left of the two 125's .Thanks to Dad in its prime it was one of the fastest Best handing bikes on the track With a hand built Aluminum swing arm Hand built Aluminum fuel tank most of the time it ran on Methanol At one time we had a 38mm pumper carburetor(GO Cart stuff ) total loss ignition we even tried nitro and put a 250 piston in it 192cc at under 200LBS it was Fun .After retiring it i put it on the street and road it to School
    So this is what i have left I figure for its 50th birthday I should bring it back to life DSCN0989.JPG DSCN0990.JPG
    #1
  2. slidewayes

    slidewayes slidewayes

    Joined:
    Nov 27, 2010
    Oddometer:
    836
    Location:
    HESPERIA CA
    1448170455906.jpg 1486511426371.jpg
    Brother (750) 1969 or 70 Myself (751) guessing 72 saddelback
    #2
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  3. poppykle

    poppykle Adventurer

    Joined:
    Jun 5, 2008
    Oddometer:
    49
    Location:
    Australia
    My second bike was an AT1. Ported, Bassani pipe and 21 inch front wheel. A lot of fun, strip down on Saturday, race on Sunday and put it back together to ride to work on Monday.
    #3
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  4. MATTY

    MATTY BORDER RAIDER

    Joined:
    Jun 23, 2014
    Oddometer:
    2,111
    Location:
    England On the Scotish border
    Awesome I am in I'll watch this to the end.
    What a brilliant thing to do get it up and running for its 50th.
    I have a strong affinity with these yamahas although I never had an at1,
    but I did have a 1973 at3 no ways a race bike just a bog standard and very battered road / trail version,
    I can remember enough about it to watch this builds progress with more than a casual interest.
    #4
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  5. flei

    flei cycletherapist

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    Apr 1, 2013
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    7,786
    Location:
    Western Mass.
    Great idea! Holy crap, that brings back a lot of memories. I may have even raced against you guys at some point! I certainly watched you race. I grew up in LA and raced those tracks in the late '60's-early '70's. Rode a stock Sachs 125. Never made it to expert though. So cool you still have the bike.
    #5
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  6. slidewayes

    slidewayes slidewayes

    Joined:
    Nov 27, 2010
    Oddometer:
    836
    Location:
    HESPERIA CA
    Don't know what kind of budget to put into this after all it is only a 300 dollar motorcycle at best . I have a front end off a 75 YZ250b with a double leading shoe brake off an early 80s Yamaha yz possibly a IT The forks have some pitting at 400-500 to re chrome or 200 for new reproductions think ill see how bad they leak, It had some Koni Shocks that i am trying to save so far in to them a day waiting for paint to dry so i can re assemble after a good cleaning should be OK impressed an the 60s technology in them hopping for the best there at 5-600$ to buy new shocks
    #6
  7. mudmonster

    mudmonster Long timer

    Joined:
    Apr 19, 2008
    Oddometer:
    1,083
    Location:
    Sydney , Australia
    Brings back some memories great work...
    #7
  8. dbarale

    dbarale Squiddly slow

    Joined:
    Oct 20, 2008
    Oddometer:
    2,172
    Location:
    Western NC
    I have two sets of 35mm Showas from early 80’s Honda XRs with good chrome for a very reasonable price (free).
    #8
  9. slidewayes

    slidewayes slidewayes

    Joined:
    Nov 27, 2010
    Oddometer:
    836
    Location:
    HESPERIA CA
    Thanks But no Thanks
    #9
  10. slidewayes

    slidewayes slidewayes

    Joined:
    Nov 27, 2010
    Oddometer:
    836
    Location:
    HESPERIA CA
    DSCN1008.JPG DSCN1009.JPG DSCN1010.JPG DSCN1011.JPG
    #10
  11. slidewayes

    slidewayes slidewayes

    Joined:
    Nov 27, 2010
    Oddometer:
    836
    Location:
    HESPERIA CA
    Some photos my progress front end shortened almost 2" still haft to make a wheel spacer for the brake took 3/4" off backing plate to center the hub, Koni shock not 1960s adjustable rebound "nice " had to make a tool to get them apart, front wheel has some cracks in it Think I'll weld them and run it ,maid some Bronze bushings today for the swing arm came out grate smooth as any new bike
    #11
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  12. Fubars

    Fubars What would Scoobydo?

    Joined:
    Aug 20, 2003
    Oddometer:
    1,998
    Location:
    Ventuna, California
    Cool project, but I like that bike lift..
    #12
  13. slidewayes

    slidewayes slidewayes

    Joined:
    Nov 27, 2010
    Oddometer:
    836
    Location:
    HESPERIA CA
    trying get little done every day Did not like the way the swing arm was working .So pushed out the bushings in the frame an maid so new bronze ones Won't push them in tell assembly Should be the fix i'm looking for. Starting on the air intake with a Still Air box/plenum DSCN1015.JPG DSCN1014.JPG

    Attached Files:

    #13
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  14. SFDemo

    SFDemo Been here awhile

    Joined:
    May 5, 2008
    Oddometer:
    290
    Location:
    Shawnee Hills OH
    My first bike was a 73 ATMX with 21 inch wheel and CT cylinder and ACK head. I'm re-building one similar now, and have it assembled but not running. I'm going to take it apart and correct some things before I ride it.
    #14
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  15. SFDemo

    SFDemo Been here awhile

    Joined:
    May 5, 2008
    Oddometer:
    290
    Location:
    Shawnee Hills OH
    [​IMG]


    Sent from my iPad using Tapatalk
    #15
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