WTB: Yamaha RT180 engine

Discussion in '2 smokers' started by KirkN, Jul 5, 2020.

  1. KirkN

    KirkN Long timer Super Supporter

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    3,343
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    Like the title says...

    Got this ol' turd for free. Not sure if the motor is rebuildable at all. Has a cracked case in the crank chamber. Might be best to start out with a better donor motor.

    PM me with what you might have.
    #1
  2. concours

    concours WFO for 48 years

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    Dec 2, 2008
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    Not sure what an RT180 is.... "RT" was the 360cc enduro designation.
    YCS180.... yes.
    Images?
    Image of the model number?
    #2
  3. Donkey Hotey

    Donkey Hotey De Jo Momma

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    1990s Yamaha play-bike line. Two stroke engine.

    [​IMG]
    #3
  4. KirkN

    KirkN Long timer Super Supporter

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    Yep, what Donkey said!

    Meanwhile, I picked up a spare parts bike with a rebuildable motor, so I'm on my way!!

    IMG_5615.JPG
    #4
  5. Donkey Hotey

    Donkey Hotey De Jo Momma

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    I have always been curious where they got that engine. It looks like the (then) recent YZ125 / IT175 air cooled engine, with an autolube pump scabbed onto the right side. Digging through the part numbers, nothing of the sort appears to be true. Connecting rod part numbers and crankshaft pieces are all different. None of the gaskets seems to be shared. Very odd.
    #5
    spokester and KirkN like this.
  6. KirkN

    KirkN Long timer Super Supporter

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    Not the YZ/IT but rather the DT175, the two-stroke dual sport play bike of the 70s. Not sold much here, but a steady seller in Central and South America.

    When two-strokes disappeared from US streets in the late 70s / early 80s, they just stripped off the lights and sold it as a play bike through the 90s.

    In fact, mine was made in Brazil, and is stamped all over as such. VIN digit is Brazil, even the engine cases have “Made in the Free Zone of Manaus, Brazil” in Portuguese cast right in.
    #6
  7. Donkey Hotey

    Donkey Hotey De Jo Momma

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    Yeah, I thought that too but, upon comparison, none of the DT175 parts appear to be shared either (looked at the 1980--last year in the US for the DT). I know they can roll part numbers for non-functional things like paint color changes so I was comparing engine gaskets and crankshaft component part numbers. Nothing shared. Again: a perplexing orphan of a bike.
    #7
  8. 8382

    8382 KLR'sKlX"sGSn'stuff

    Joined:
    Jul 19, 2011
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    Up here in Canada (probably US also), the DT 125 and 175 shared a lot of parts from 77 till 81, the RT180 then used some of the parts also in to the 90s.
    They were all basically the same motor and chassis except for the larger cylinder and piston in the 175. Fairly bulletproof. I have a 1979 DT125 since it was new. Still running, but in need of a cosmetic restoration. Maybe this winter! My best friend also had one. Was a pretty great machine in its day, certainly ahead of the competition in the dual sport segment... Crap, I'm gettin' all misty :2cry
    KirkN, they are a fun trail bike for singletrack and the like. Pretty light and flickable. Repairs are fairly simple on them, Good luck with it. You can definitely make one good one out of two. Keep us posted on your progress. :lurk:drink
    #8