engine won't start, new cdi & new magneto

Discussion in '2-Stroke Engines' started by xRegginoy, Jan 26, 2010.

  1. xRegginoy

    xRegginoy Member

    So about a month ago, I lost the clutch cable end keeper thingie ma bob. I wasn't sure where to purchase another so I just took a break from the bike. Then my dad helps me create a make shift one, and also he replaced the spark plug with an NGK one that I purchased from SBP when I bought the front mount.
    I test out the bike, and it started easily even with it being like 30 degrees out. I start to go around the neighborhood and out of no where, the bike stops. It sounded to me like when the fuel valve is left closed, I reach down and to my surprise, the fuel valve was open. I recheck the wiring, and all is good and it still wouldn't start. I took the bike back home and after some voltage testing by my dad, he said that it was either the CDI or Magneto that broke. He said that the CDI was more than likely the problem. I buy a new CDI, and replace it... no cigar. I buy a new magneto (along with some other parts) from thatsdax, replaced it about an hour ago, and no go. I've checked the wiring multiple times. I've tried it with both the stock and NGK sparkplug yet it won't start. The kill switch is not connected so that can't be it.

    What am I missing? :p

  2. GearNut

    GearNut Active Member

    Turn the gas on?


    Have you checked it for spark, or have you just peddled your hiney off hoping it would start?

    It could also be a massive intake leak, loose cylinder head, faulty carb, bad seal on the crankshaft (either end). You just have to check them all, starting from the easiest to the hardest.
    An engine needs 4 things to run: Air, fuel, (properly metered), compression, and heat (spark from spark plug in your case).
  3. Check everything again and don't give up. And you do know how to use the choke don't you? choke up when starting and then down after its running.
  4. swifty

    swifty New Member

    if your sure the spark is ok, drain the stale fuel out & refill with fresh fuel then turn fuel tap on & loosen the drain screw on the carby bowel to check if fuel is running out.float needle may be stuck from sitting.
  5. AussieSteve

    AussieSteve Active Member

    To test for spark, remove the spark plug, refit it to the HT lead, then lay it on the head so the plug body is earthed. Next lift the rear wheel and spin it. Look for spark at the spark plug gap.
    You might need a helper to do this.

    ... Steve
  6. motorpsycho

    motorpsycho Active Member

    Are you running a fuel filter? if so, check the filter because it may be plugged up. with the bike sitting for so long, any sediment that may have been in the gastank would have settled to the lowest point in the tank (that would be the fuel petcock) and as soon as you open the petcock and fuel starts to flow, all the sediment would be sent directly into the fuel filter (or carb if you are not running a filter).
    check the spark plug wire end. if you are runnning the stock plug wire, they are ****, and the end that goes onto the spark plug sometimes will come apart. If that happens, there will be no contact between the wire and the plug, making no spark.
    check for spark, check to make sure fuel is getting into the carb., make sure the choke is not on after you get the motor running, and check your air filter.
    Check the simple things first before jumping in and assuming that it's an expensive or hard to replace part.
    There could also be moisture in your gas tank from it sitting for so long, so i woudl also drain the fuel and replace it with fresh stuff.
  7. xRegginoy

    xRegginoy Member

    Thanks for all your advice. Before applying any of your suggestions, I read a thread some where that someone installed their magneto, backwards. Soo, I thought I did, so I flipped my magneto over. And lo and behold. It works!

  8. arceeguy

    arceeguy Active Member

    Hmmmm - might be a good way to get a HT to operate in reverse rotation.............
  9. AussieSteve

    AussieSteve Active Member

    Interesting - it must have been firing at bottom dead centre before. I don't think that would help it run in reverse, though. I think that these engines might already run in reverse, if someone wanted to try. Not me.

    ... Steve
  10. arceeguy

    arceeguy Active Member

    You're right. Nevermind!
  11. Al.Fisherman

    Al.Fisherman Active Member

    Steve...think if the plug was firring at BDC, there is no way it will run, either way...No compression in the fire cycle.
  12. AussieSteve

    AussieSteve Active Member

    I used a bad choice of words, Ron. I meant 'sparking' at BDC, not firing. (The engine 'wasn't' running, because the maggy was upside-down.)

    ... Steve