1973 yamaha rt 360 build

Discussion in '2 smokers' started by crawler07, Nov 1, 2010.

  1. MightyChosen1

    MightyChosen1 I wanna be sedated

    Joined:
    Sep 17, 2008
    Oddometer:
    1,716
    Location:
    Central,IL
    Sweet Bike . I just stumbled across this thread. I just picked up this 73 360 for $250 . Runs great but needs some cosmetic work. It came with a lot of extra parts including a vintage Hooker exhaust the I might install soon.

    This bike is really an animal compared to my DT-175. Gobs of torque and hardly any brakes.:evil

    [​IMG]
    #41
  2. crawler07

    crawler07 Adventurer

    Joined:
    Oct 19, 2010
    Oddometer:
    70
    Nice bike and you got it for one hell of a price:eek1 I paid about what you did and then I put way to much into it so far LOL. Your not kiddin about the torque on these things I can only imagine what an inline four 2 stroke would run like..
    #42
  3. spo123

    spo123 Man About Town

    Joined:
    Nov 7, 2006
    Oddometer:
    989
    Location:
    North Shore Mass. USA
    Well, good luck with piston modification.....I do not know of anyone who has replaced the reed valve piston with one without the ports.......Let us know how it goes....:evil:freaky
    Congratulations on the crank seals.....How difficult were they? Did you have to split the cases for one of them?
    Love old two strokes!
    spo
    #43
  4. crawler07

    crawler07 Adventurer

    Joined:
    Oct 19, 2010
    Oddometer:
    70
    I thought I was going to have to split the cases, but the seals dont have an outer lip so it was as easy as screwing a screw into the side of the seal and giving it a good yank ..then tap in the new one.
    #44
  5. whaleater

    whaleater n00b

    Joined:
    Mar 31, 2011
    Oddometer:
    1
    hey mate. i have a full manual for the RT1-3's in pdf format if you want it. more than happy to send it to you via email, just let me know.
    in the meantime, can you tell me where you got your gas cap? that this is amazing!!

    great thread by the way. looks awesome so far.
    #45
  6. smokeeater495

    smokeeater495 Been here awhile

    Joined:
    Oct 14, 2008
    Oddometer:
    615
    Location:
    N.E. Indiana
    Return the incorrect piston and order the right one. Self porting the skirt will result in a poor running machine or a blown-up motor.
    #46
  7. smokeeater495

    smokeeater495 Been here awhile

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    Oct 14, 2008
    Oddometer:
    615
    Location:
    N.E. Indiana
    I just spoke to my friend who used to make pistons for Zollner. He said by drilling your own ports you will unbalance the piston and definately weaken the skirt. Guaranteed you will destroy the engine:cry.
    #47
  8. ctune80

    ctune80 Been here awhile

    Joined:
    Sep 1, 2010
    Oddometer:
    240
    In the early days of MX it was common to drill and modify piston skirts on
    race bikes. I've seen lots of bikes that have had modifed skirts back when
    reed valve kits were coming on the market to put on the old piston port bikes.
    Considering this bike won't be a racer I would think there would be little risk.

    Judging by the quality of the work I'v e seen on this project I'm pretty sure it
    will be done right. Make sure to chamfer the openings to eliminate sharp edges
    stress risers and prevent cracking.

    ___________________________________

    The Crux of the Biscuit, is the Apostrophe.......
    FZ
    #48
  9. LasseNC

    LasseNC XSessive!

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    Jan 27, 2008
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    1,093
    Location:
    Denmark, Danimarka, Danmark, Dänemark
    +1
    #49
  10. crawler07

    crawler07 Adventurer

    Joined:
    Oct 19, 2010
    Oddometer:
    70
    thanks for all the replys on the piston question fellas, i decided to go ahead and cut the ports in the piston and i have ridden it a few miles already and the vibrations arent a problem. The ride was good and their was far less vibration than before the rebuild WOO HOO:clapbut Its not all good news this bike is kicking me back like crazy and im thinking its dur to being a bit out of time maybe to advanced?? Does anyone have any tips on adjusting timing on one of these? Im assuming the stator plate is adjustable? I cant find my flywheel puller I used when I replaced the crank seals a while back.. I have made a good bit of progress on it and here is a few pics for you guys..


    [​IMG]

    [​IMG]

    [​IMG]

    Didnt do good with taking pics along the way, but i will be sure to post more detailed pics of the cb 350 thats the next project
    [​IMG]
    #50
  11. Twin-shocker

    Twin-shocker Long timer

    Joined:
    Jan 28, 2012
    Oddometer:
    1,673
    Looks a good job.............I have a guy here in the UK who makes very hight quality pistons, and those he makes for me for piston port motors, are exactly the same as the ones for reed valves, other than the reed ones have boost holes milled into them.

    I guess your bike might have points ignition, and if so you could probably stop kick backs by closing the points gap a little?
    #51