My Bike is a Pig

Discussion in '2-Stroke Engines' started by will_start, Mar 20, 2009.

  1. will_start

    will_start Member


    I've had my petrol bike stored under my house for like 6 months.
    It used to run when I last put it there.
    So, as I have moved back to my house full-time, I decided
    I stubbornly decided I wanted to get it up and running again. :euro:

    More so it was calling to my tinkering addiction.
    So here's the list of things done to it so far:

    1. I put its wheels back on. Big help I know.
    This bike actually had a snapped frame, which I had rewelded
    before cold storage. So it was many attempts to get the back wheel
    to align properly. :82:

    2. Test Spark. Yes it has spark.
    3. Replaced Spark Plug Cable, with a lawn mower,
    variety cable. This was given to me by a guy who repairs
    4. Clean out Carby. Did a thorough petrol clean out.
    5. Try starting with Ether, this did nothing. :furious3:

    Things to try:
    A. Retest spark with current in use plug & lead.
    B. Buy more Petrol, fill up tank. This has given a good start before.
    I can use same fuel with my Lawn mower and it works fine !!!
    C. Buy a new spark-plug.
    D. Test Magneto's Resistance.

    I have documented this bike issues via vids and posts here before.
    But figure all the effort I am putting in needs a new post. :banghead:

    It reminds me why I went an electric with 12 month Warranty...:tt1:

  2. Zev0

    Zev0 Member

    Are you using the same gas that was in it 6 months ago. If so, that is probably your problem.
  3. seanhan

    seanhan Member

    Yea get some new gas and flush your tank a little bit ...
  4. will_start

    will_start Member

    ok you got me, same fuel as before, like six to 9 months old.
    it ran in the lawn-mower really well tho.
    why is that ?? :57:
    they have the same ratio.
  5. bamabikeguy

    bamabikeguy Active Member

    Mixed gas, esp. the ones with high oil ratios, is only good for 2-3 weeks, then it separates. I pour old gas into the lawn mower, (which has an oil pan) or the car, then mix another batch.

    Here in the states, I avoid "cheapie" gas like the plague (water content, non-uniform ethanol standards), and use 89 octane from a major brand name company.
  6. Mountainman

    Mountainman Active Member

    yes have found no harm what so ever just pouring the old into the car or truck
    this reminds me -- I have some very old gas mix out there right now

    ride that thing
  7. will_start

    will_start Member

    I almost lost it, felt like i was going to go over the front wheel.

    Ok, new fuel made a slight difference, I get one, two or three kicks back from the engine after getting the bike up to about 15 km/hr. One kick back happened when I was adjusting the choke, felt like i was going to go over the front wheel. :ee2k:

    So, to my next step as above for me,
    A. & then C. I'm glad i wrote the list, keeps me on track.

    ...thanks for listening/reading/responding...
    Last edited: Mar 21, 2009
  8. will_start

    will_start Member

    Ok quick update.
    I tested the spark-plug and I see spark. point A above.
    Tried again to start the bike with Ether, and got no start...
    Am buying a new spark-plug at some point soon. C.

    I read a post from Bolts Missing, that its possible to have & see spark
    and still have not enough spark to get a start. Changing plugs helps eliminate that...
    Last edited: Mar 24, 2009
  9. bbb

    bbb Member

    OLD gas will WRECK a spark plug instantly.
  10. will_start

    will_start Member

    thanks for the info...
    When you say wreck, would that mean no spark ? or weak saprk
    As I was seeing spark last night, you just can't guage how
    strong it is by looking at it, whilst holding the plug and wheeling your bike around your back-yard in the dark.
  11. kjparker

    kjparker Member

    Havent read the entire thread, but this is what I would do.

    * Replace spark plug lead with automotive one.
    * new plug (think I have one)
    * half a cup of metho in the tank with the fresh fuel to absorb any moisture that might be in there
    * new fuel filter
    * pull carby aprat, liberaly clean with carby cleaner, then re-assemble.

    If it doesnt start after all that, then your boned!
  12. bbb

    bbb Member

    even in a car it will run poor once it has been fouled...even worse with old gas.
  13. motamyk

    motamyk New Member

    crank seals could have deteriated
  14. will_start

    will_start Member

    Should you see the neddle come out of the jet hole ?

    Thanks for ideas, all.

    I've already cleaned the carbie.

    By the sounds of those sugguestions, I may as well buy a new motor.
    Crank seals, new fuel filter, new plug leads.

    How would I know if its the crank seals ?
    I'll try the metho in the tank. As I have half a cup left in a bottle.

    I have already cleaned out the carbie.
    I wish there was a way to work out the compression
    of the motor, without another purchase.
    The cylinder on this motor had a hole in it, but it still ran.
    I repaired it with steel cement, but I won't know if thats any good.

    I can still ride the bike however, even with the motor on it,
    not starting.

    I purchased and installed a new spark plug.
    Made no difference. I'll try regap it,
    maybe another go with the ether.

    One last question, for anyone when you look into the back of the carb,
    then twist back the accelortator,
    Should you see the neddle come out of the jet hole ?

    I get the same change in noise I always used to pre motor start.
    when I twist back the accelrator, when riding.

    AT some point,
    I'm going to try that reduction of the magneto gap mentioned in another
    post, its supposed to increase your spark strength.

    I wonder if nitrous would make this engine start.
  15. will_start

    will_start Member

    The bike works now, I found the PIG.

    The bike works now.

    I tried removing the Kill Switch out of the wiring, by going
    direct to the CDI. BLUE to BLUE BLACK to BLACK.

    The bike then started up straight away.

    So I either wired in the kill switch wrong. :whistling:
    Or it has developed a fault of its own.

    Either way, I went for a 30km ride on the weekend, through all the beachs in
    my local area. Which was way cool.

    Thanks everyone for the advice.
  16. arceeguy

    arceeguy Active Member

    I think if the CDI is wired backwards, it will fire at BDC. So you were getting spark, just not at the proper moment! Glad you got it running!
  17. will_start

    will_start Member

    I still want to use the kill switch.

    I think I had it wired into the Blue wire.
    I am going to try wire it into the black,
    as the "Clutch off" technique, I think is no good for the motor.

    Its such a simple circuit, I can't believe it was the source of the
    no start.
  18. arceeguy

    arceeguy Active Member

    I wire the kill switch to the white wire and black wire. When you short out the white wire to ground, it will kill the spark just as effectively as shorting the blue wire to ground. And then you won't have any high voltages at the kill switch to worry about. If water gets in the kill switch and it is wired to the blue wire, the moisture could be enough to leak enough current and kill the spark.

    Heck - this is probably the real reason why these engines seem to quit after you ride them in the rain - and replacing the magneto coil and CDI doesn't fix the problem.
    Last edited: Mar 29, 2009
  19. will_start

    will_start Member

    I've read that using the white wire to stop the motor will kill the magneto.
    The kill switch I bought is water-proof.

    I sealed everything I could with Window Sealant.
    IE the magneto gasket.

    One thing I didn't mention is about 8km from home the bike just stopped.
    I looked down and the spark plug was out.

    I had no tools on me and no mobile phone in case I was stuck...
    So I waited for the plug to cool, then finger tightened it back in,
    and I'm away again.

    I tightened the plug in proper when I got home.
    When I had this happen once before, it broke my plug lead.
  20. arceeguy

    arceeguy Active Member

    I haven't had a problem. (nor any of my customers that have purchased engines/bikes from me) Can't think of any reason why that would be the case.