TY250 project

Discussion in 'Some Assembly Required' started by Junglejeff1, Nov 1, 2018.

  1. Junglejeff1

    Junglejeff1 Long timer

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    I have been looking around for at least a year for a 74 TY250.It was my 1st bike in 1976 when I was 13 years old.A friend sent me a link on a Facebook site and I closed the deal on one yesterday for 650$.I have been doing some searching and have found out I have the cat version. It has pegs a little farther forward and a few other different parts to make it more of a trail bike.I figured it would be a cool bike to ride around the trails with wife on her ttr125.Also would be neat to do a vintage trials comp with it.Bike is pretty original and motor has decent compression but have not started it yet.So my journey started today with a good power wash before taking it apart.Will post picks as I progress.Also looking for a stock front fender if anyone has a lead. 20181031_183533.jpg
    #1
    Motociclo, Amphib, dwdantzler and 2 others like this.
  2. FR700

    FR700 Heckler ™©®℗

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    :lurk
    #2
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  3. r60man

    r60man Long timer

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    Looks in decent original shape. I have a TY250A that I am trying to sell. But I am looking for more than $650, you got a good deal. They are getting more and more valuable.
    #3
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  4. Junglejeff1

    Junglejeff1 Long timer

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    20181102_123656.jpg checked spark on bike and have a nice big blue spark.Pretty surprised as bike sat for 4 years and has point ignition .I drained the mud colored fuel out and gave the carb a cleaning and want to run it before I pull it apart to show me any issues. Tank is rusty inside so going to try a viniger cleaning that I have seen on utube.Picked up some new fuel line and in line filter and heading out to garage to put carb back on and see if it runs good.
    #4
  5. Junglejeff1

    Junglejeff1 Long timer

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    Quick run went bad but told me a story.Have some piston slapping going on and carb is not right. Would run wide open with choke and idle with no choke. I noticed previous owner had float set so it barely closed inlet needle.Had to reset to that to run so guessing floats are sinking. Have to see what parts are available for TK carbs.

    Attached Files:

    #5
  6. UstaKood

    UstaKood Been here awhile

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    Giving up already !?

    Get it sorted and I'd bet you'd like it .
    #6
  7. r60man

    r60man Long timer

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    There are plenty of parts available for TYs. Use your Google-fu and you will be fine. Also plenty of knowledgeable people around that can point you in the right direction.
    #7
  8. Junglejeff1

    Junglejeff1 Long timer

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    The know how is not the problem. I started adding up how much it would cost to repair and not sure it's worth it.So far I am looking at a new carb,tires,chain,sprockets, brakes.Been awhile since I did a restoration and forgot how it adds up.If I don't sell it i will restore it.I should keep going as I do like these bikes.
    #8
  9. Junglejeff1

    Junglejeff1 Long timer

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    Ok guys I am all in.Screw it I'm going to go balls out on it.Just found my crank bearings are loose and pulling the motor now.You guys get to watch me throw money at this bike.Wifey said go for it.
    #9
  10. Junglejeff1

    Junglejeff1 Long timer

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    20181105_191142.jpg pulling motor and engine mount is broke on right side.Will be some welding involved. 20181105_191142.jpg
    #10
  11. Junglejeff1

    Junglejeff1 Long timer

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    Maby not the carb that was making it run so bad.Were the heck are the missing chunks? .I will search lol.
    #11
  12. Junglejeff1

    Junglejeff1 Long timer

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    Woops,hit send before pic loaded.Going to need a rod kit also as I have some big end play. 20181105_194207.jpg
    #12
  13. Junglejeff1

    Junglejeff1 Long timer

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    Case is glued on.heated with some map gas a bit and shoved a razor blade into gasket to break seal.came off easy after I got it started. 20181105_201617.jpg
    #13
  14. Junglejeff1

    Junglejeff1 Long timer

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    Cylinder is original so can easily bore 1st oversize which is cool.Measured bore and barreled out at ports about .003" so close to limit on wear.Will clean up ports and mod things a tad.Plan is to bring up exaust port 1 mm and shave head a bit and rechamber.Yami is famous for too loose a squish band so this will deal with that.Will help mid range tork some and makes them jet cleaner . 20181105_204154.jpg
    #14
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  15. UstaKood

    UstaKood Been here awhile

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    :clap

    Yammies always seem to have had a bit of rattle , but Hochimama ! Surprised it even ran !

    I've had mine many years . Other than a little port / polish , biggest improvement was the Mikuni and Boysen reeds / spacer mod . It's a tractor . Wasn't ever aware of squish issues , but I know that was the case with the mono shocker .

    Timing definitely matters . You'll want to get it dialed in before you get back in the frame as there is little clearance between the head and frame .

    Speaking of the frame , the swingarm pivot removal can be an adventure .

    I've bought most of the blingey things from B&J racing over the years and Bob is very knowledgable with the TY's .

    Nice bones though . My buddy had the conversion back in the day .

    :thumbup IMG_1130.JPG
    #15
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  16. Junglejeff1

    Junglejeff1 Long timer

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    I talked to Bob on phone and he seems to know them inside out.Going to get his mikuni carb and the reeds.Not a bad deal as it comes ready to go with cable and domino throttle. All balls main and seal kit only around 60$.Still have to check on a rod kit.Most likly hot rods have one as this motor has many dt parts in it. Found out dt has same port specs wrapped in a different cylinder casting.The extra power comes from bigger carb,Reed block and exaust.
    #16
  17. Junglejeff1

    Junglejeff1 Long timer

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    I'm trying to find a cast piston as they can be set tighter.Not a forged piston fan in these old air cool bikes.I refuse to use wisco anymore.
    #17
  18. Junglejeff1

    Junglejeff1 Long timer

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    20181108_162024.jpg 20181108_162039.jpg 20181108_162109.jpg welder together some scrap today to make a tool to push out crank.Worked well and everything went smoothly. Going to send crank to B&J Performance next week and have him put a new rod on it.Has been awhile since I did one so would rather pay the pro i ordered new mains from all balls (even includes crank seals)for 60 bucks.Ordered a new clutch basket shaft support bearing from yamaha to be safe.
    #18
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  19. Junglejeff1

    Junglejeff1 Long timer

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    I think I am going to repaint bike in non stock color's also.Not doing this to be all factory lol.I don't care for yellow.
    #19
  20. Junglejeff1

    Junglejeff1 Long timer

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    Took more apart today.Swingarm was a small fight to get pivot bolt out.Spun the shaft with a impact wrench and it freed it up so I could drive it out.Was not rusty but stuck pretty good.After this pic was taken my wife held bike from flopping and took the fork assembly off.Will get frame blasted and fix what is broken and go over a few welds. 20181110_161731.jpg
    #20
    Foxed101 likes this.