/ Register

Help Tacho drive ratio? 81 GSX250

Discussion in 'Suzuki 250cc Twins' started by Bryce, Feb 5, 2015.

  1. Bryce

    Bryce Member Premium Member

    Messages:
    6
    Likes Received:
    1
    Trophy Points:
    13
    Joined:
    Jan 2, 2015
    Gender:
    Male
    Location:
    Melbourne
    My Bike:
    81 gsx250
    I'm hoping someone can help me out as I want to get a aftermarket tacho but need to find out what ratio gear drive I have. It's a 1981 gsx250 and my options are 1:4, 1:5 or 1:7
     
    Bryce, Feb 5, 2015
    #1
  2. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

    Messages:
    6,406
    Likes Received:
    4,793
    Trophy Points:
    1,148
    Joined:
    May 4, 2013
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Tamworth, NSW
    My Bike:
    1937 Royal Enfield 250, CF Moto 250 V5, Honda's XL250, CBR250, FT500 plus a few others.
    Clean the end of the tacho cable and wrap a piece of masking tape around it leaving a piece sticking out like a little flag. Take off necessary cover to get to nut on end of crankshaft and fit a socket on a fixed bar, then rotate the crank 10 times and count the turns of your tacho cable flag. This will give you a ratio, ie 10 crank turns to 2 cable turns = 5 : 1.
     
    • Like Like x 2
    Murdo, Feb 6, 2015
    #2
  3. Brett GSX

    Brett GSX Member

    Messages:
    11
    Likes Received:
    2
    Trophy Points:
    13
    Joined:
    Sep 11, 2014
    Gender:
    Male
    Location:
    adelaide
    My Bike:
    Suzuki GSX 250 1981
    Hi Bryce. Tach ratio is 1:4. I tested the mechanical aftermarket one I bought against the electronic tach the guy before me had wired in, and RPM were identical.
     
    • Like Like x 1
    Brett GSX, Mar 2, 2015
    #3
  4. Bryce

    Bryce Member Premium Member

    Messages:
    6
    Likes Received:
    1
    Trophy Points:
    13
    Joined:
    Jan 2, 2015
    Gender:
    Male
    Location:
    Melbourne
    My Bike:
    81 gsx250
    Thanks Brett! I have sold the bike since this post but cheers for the help.
     
    Bryce, Mar 2, 2015
    #4

Share This Page