CT 125 Won't Start

Discussion in 'Thumpers' started by backcountryrider15, Dec 2, 2012.

  1. backcountryrider15

    backcountryrider15 Adventurer

    Joined:
    Mar 10, 2012
    Oddometer:
    24
    Wanting to strap dynamite to this bike right now!

    I did a full rebuild on the top end, bought a brand new carb, adjusted the valves, bought the main wire harness, and tied the coil wire/points wire to the main wire harness (instead of using the jumper wire off the stator wire harness with a wire nut to connect the 3 together) and the bike started, but when I gave it gas it died. I thought it just needed to warm up or something, but it wouldn't start. I went back to the old method and took the main wire harness out of the equation, I used the jumper wire off the stator wire harness as I did when i first started the rebuild and nothing.

    I took the carb off, it's brand new and good.
    I took the spark plug to ground and kicked, I have spark.
    Seems like I have fuel and spark, not sure how all the sudden I would loose compression after a brand new top end.

    I'm thinking either stator is done or points contact. Not good with electrical, not even sure how to test them or if they are even the problem.

    What is going on here???? Help would be greatly appreciated from you fellas with mechanical experience. I'm on a fine line thinking of taking it to the shop, but knowing I'm going to get ripped off bad by a shop.
    #1
  2. backcountryrider15

    backcountryrider15 Adventurer

    Joined:
    Mar 10, 2012
    Oddometer:
    24
    I forgot to mention I installed a brand new coil and spark plug at the beginning of this project.
    #2
  3. CaptTeach

    CaptTeach Been here awhile

    Joined:
    Dec 7, 2008
    Oddometer:
    209
    Location:
    Grenada - MS....... not the Island!!!!
    First off since you have spark it has nothing to do with any of the electrical stuff - it is going to be strictly a fuel or timing issue. Just because the carb is new does not mean that it is flowing anything thru it

    Lets start with the basics Check the Fuel Level in the tank and make sure the petcock is on and fuel is getting to the carb.

    Run the mixture screws in and then back out 1.5 turns for a base setting

    Be sure that the slide in the carb is moving freely

    Put a fuel filter between the tank and carb - a small piece of trash from the tank can cause all sorts of havoc!!

    Give it a shot after that to see if it fires up - if not check the timing to be sure the spark is happening at the right point in the stroke cycle
    #3
  4. backcountryrider15

    backcountryrider15 Adventurer

    Joined:
    Mar 10, 2012
    Oddometer:
    24
    So I timed the valves, cleaned the points contact faces, timed them so that at there most separated time it's 14 thousandths, and still nothing. Would love some help right about now. I can drip fuel out of the carb drain screw so fuel is in the bowl.
    #4
  5. CaptTeach

    CaptTeach Been here awhile

    Joined:
    Dec 7, 2008
    Oddometer:
    209
    Location:
    Grenada - MS....... not the Island!!!!
    Open the drain screw and see if a good stream of fuel comes out - not just a drip and it should keep flowing. Catch what comes out in a glass jar and make sure it is fuel. Is this a vertical or horizontal engine??
    #5