Kawasaki AR80

Discussion in '2 smokers' started by Me and my monkee, Jan 23, 2012.

  1. Me and my monkee

    Me and my monkee Out makin' Monkee Maps

    Joined:
    Apr 13, 2007
    Oddometer:
    1,109
    Location:
    Augusta GA
    Any experts here?
    I had one back in my misspent youth, and recently picked up another. Doesn't seem to run as I remembered. But before I start with the questions just figured I'd see if anyone here has knowledge. No much info around on these bikes.
    #1
  2. Brunow - 007

    Brunow - 007 Bantam Fever

    Joined:
    Oct 26, 2009
    Oddometer:
    313
    One of the fastest 50cc i have driven!
    Nice power curve if you like to shift a lot! :wink:
    #2
  3. Shocktower

    Shocktower Long timer

    Joined:
    Jul 27, 2009
    Oddometer:
    9,535
    Location:
    Oregon City Orygun
    How long has it been sitting, and what are your intentions restoration Mods :ear
    #3
  4. scrambler73

    scrambler73 Been here awhile

    Joined:
    Feb 7, 2010
    Oddometer:
    127
    Location:
    where I am supposed to be.....
    I had one for a while. It would do just shy of 70mph bone stock. I was even stupid enough to bring out in traffic on the highway one day.....ever ride your bicycle at highway speeds next to 18 wheelers before?
    S-C-A-R-Y

    they are simple engines..no different than anything else. whats "wrong" with it?
    #4
  5. Bud Tugly

    Bud Tugly Gnarly old curmudgeon

    Joined:
    Feb 14, 2007
    Oddometer:
    256
    Location:
    Formerly Ishpeming, MI now Eugene, OR
    A frequent problem with 2 strokes that have been sitting unused is leaky crankcase seals. Since the crankcase on 2 strokes forms part of the intake system, if those seals leak it'll mess up your fuel/air mixture big time.
    #5
  6. Me and my monkee

    Me and my monkee Out makin' Monkee Maps

    Joined:
    Apr 13, 2007
    Oddometer:
    1,109
    Location:
    Augusta GA
    Thanks all.
    I remembered a top speed of just shy of 70 back in the day, but this one can barely crack 55 on a flat road. Though my old one did have a Micron race pipe:wink:

    I got all the intake system back to stock but felt the bike bogging in the last 10% or so of throttle. Removed the airbox silencer to let more air in and it ran like pure shit, sputtering and all. Put a piece of uni-foam in the circular intake on top of airbox, without the airbox silencer (this is how it was when I bought it) and things got better. Better throttle response, and better top end, but barely.

    I just want to get it running right, and then worry about tuning etc. after that.

    I have not checked jet sizes yet...I guess I need to do that first, make sure the carb is all stock. Carb needle looks very straight, hardly any taper at all.

    Crankcase seals? Easy fix?
    #6
  7. scrambler73

    scrambler73 Been here awhile

    Joined:
    Feb 7, 2010
    Oddometer:
    127
    Location:
    where I am supposed to be.....

    How much did you weigh "back in the day?".... If you put on 100 lbs, that poor little bike is giving you all she's got at 55....:rofl

    To check crankseals, you'll need to do a leak-down test. Blocking intake and exhaust ports, making sure everything is tight (head, carb manifold, etc)... Pump in 6 lbs (hand pump..NOT A COMPRESSOR) of pressure, and if it holds for 6 minutes, you are good as far as "pressure" goes. Then use a mity-vac and put 6lbs of vacuum to it.. If it holds for 6 minutes, the crank seals are good. If it doesn't hold on either test, squirt some soapy water on "suspect" areas to see if there is a leak in a location other than the crank.

    Im not sure if you can replace the AR80 crank seals without splitting cases? If you can, then yes... pretty easy fix. But if they are "ribbed" seals (where the cases hold them inplace), then you are stuck splitting cases.

    Probably not a bad idea to buy the Sudco Mikuni Carb Tuning manual.. It will teach you about each carb circuit and its job in fuel/air delivery.
    #7