Yamaha RX50 - 250 Swap

Discussion in '2 smokers' started by PBlack003, Jun 25, 2012.

  1. PBlack003

    PBlack003 FNG

    Joined:
    Jun 24, 2012
    Oddometer:
    3
    So I recently purchased a 1982 Yamaha RX50 that had a 250 swapped into place for $50.00 with a title, everything is almost complete, it needs a new rear sprocket and a clutch cable. Anyway my question to everyone here or anyone here is will the stock electronics work from a 50cc motor to a 250cc motor and what size rear sprocket is recommended for this size bike that has been upgraded to a 250. ??? I may have more questions later on i don't have a clutch cable to on it now so i haven't started it at all, i don't even know if it works, but the carb looks great and it was winterized and stored in a storage unit from 1992 on. the guy i purchased it from only saw his dad ride it as he was a kid, but his dad passed in the early 90's and the mom just recently let her son sell it. anyway this is my first "older bike" and my first "2 stroke" so im still learning about them and because it's such a limited bike i haven't found much info except that the YSR50 shares some stuff like the motor.. any info or help would be appreciated.. also this is my first post so mods if im in the wrong spot, my bad...
    #1
  2. FloridaSteve

    FloridaSteve Long timer

    Joined:
    May 24, 2006
    Oddometer:
    2,084
    Location:
    Jacksonville Florida
    Aw man lets see some pics of THAT! That's a pretty tiny chassis for such a big mill. Should be interesting. I don't know about the electronics but try to find out what the original gearing/wheel size was on the 250 and do the math on the sprocket. Sprocket specialists can make just about anything.
    #2
  3. JeffS77

    JeffS77 cheap bastard

    Joined:
    Apr 23, 2006
    Oddometer:
    3,378
    Location:
    Riverside , CA
    the 250 probably runs a 520 chain and that RX rear sprocket probably takes a 428..need to get a 520 sprocket for the rear
    #3
  4. PBlack003

    PBlack003 FNG

    Joined:
    Jun 24, 2012
    Oddometer:
    3
    Will post pics in the morning, I have been hesitant to buy a rear sprocket and chain because of that reason and yeah it's a small frame but the 250cc motor actually fits like a glove! Thank you both for a good start! Pics soon!

    P.s. are pics here like other forums ? Can I inbed a link from photobucket ? If so pics tomorrow for sure !
    #4
  5. PBlack003

    PBlack003 FNG

    Joined:
    Jun 24, 2012
    Oddometer:
    3
    As promised, just a week or 2 later :/ this in my 50 dollar bike!



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    #5