Fuel,Fire,Compression,And you think it would run

Discussion in '2-Stroke Engines' started by meatball758, Apr 19, 2009.

  1. meatball758

    meatball758 Member

    I am pulling my hair out...good spark..I even pulled the mag stator out to see if the key was sheared but it's not..it's getting fuel, i disconected the kill switch so no problems there...motor has less than 30 miles on it(its a new build) I had the mixture fat and was having sputtering while riding so i though i would pull the plug a clean it..Since then it has not run again...So i installed a new plug, plug wire, and a new NGK plug connector..Good blue spark but it wont run..It wont even spudder..It's like it wont fire under compression...I cleaned the carb and made sure the exhaust is not plugged...Any help...It's a new build and I wanna ride....HELP !!!!!!!

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  2. Mountainman

    Mountainman Active Member

    just wondering meatball

    does it fire a little with some gas poured into the jug ??
    if so -- carb problem -- one would think

    if no fire with gas into jug plug hole
    would have to be some kind of elect problem

    I think

    get that THING up and running sideways
  3. meatball758

    meatball758 Member

    Well Mountianman, it is getting fuel..i am going to spray a little starting fluid in there to see if i get a spudder...
  4. meatball758

    meatball758 Member

    Rats...still nothing......:confused::annoyed:
  5. Mountainman

    Mountainman Active Member

    so no spudder -- sounds like elect -- weak spark maybe ???

  6. ottosear

    ottosear New Member

    Crankcase full of raw fuel ?

    My snowmobile did that once. They put a drain plug on the bottom of the crankcase. Removed the plug, out drained some gas. Took the spark plug out and pulled it over a few times. It ran well after that. Perhaps you have a similar problem ? :idea:
  7. meatball758

    meatball758 Member

    :confused:Yea ill have to reserch the output of power from the coil......Any body eles wants to take a stab at it???????
  8. POPS

    POPS Member

    Heres a longshot but you say you have compression. Did you check with a gauge or your finger? If you checked with your finger I wonder if it is possible that you have a broken ring and it does not show it until there is a tight seal like a spark plug or a compression gauge? Like I said,It's a long shot...POPS
  9. fetor56

    fetor56 Guest

    Wierd problem...try putting the bike back to standard & see if that makes any difference,possibly one of the new parts is faulty.
    Did anything happen between the time it was working(but spluttering) & u had the chance to work on it?
  10. biken stins

    biken stins Member

    Have you tried closing the plug gap a bit ?
  11. BSA

    BSA Guest

    pull your plug and see if its wet, you may be flooded. Cleaning up your plugs is never a bad idea.

  12. BoltsMissing

    BoltsMissing Active Member



    The limitations on the forum won't allow a certain part of the word within the URL to appear.
    but's called: startyab*st*rd.com
    where there is a * symbol, replace with the letter a
    Or, I was able to capture a promotional picture with the full name of the product, "startya*******" in the background, just incase.

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  13. Junster

    Junster Member

    Did you get it to run? Check the plug right away after trying to get it to start. If it's really wet then it's flooding. Check the intake for leaks. Pull the bowl off the carb and check the float. You can use a piece of fuel line. Blow thru the fuel line and lift the float to see if it shuts off the flow. While it's off push a thin wire thru the jet to make sure it's clear. GL
  14. cpuaid

    cpuaid Member

    won't start...

    i've just completed a new slant head build which ran perfectly for about 20 miles. the next day it just wouldn't start up. it sputtered like it wanted to start but wouldn't go. verified it was getting fuel. verified spark. disconnected kill switch. still nothing. as a long shot, plugged and unplugged the CDI a few times. fired right back up again. just a bad connection that wasn't obvious to the eye. thank God these things are very low tech!
  15. ottosear

    ottosear New Member

    Another thing that we would do to start a wet engine... Heat a new plug with a propane torch. 20 seconds, place in head a couple of turns. connect high tension lead. See if it starts. :snobby: Or not.
  16. dancycle

    dancycle Guest

    What is the easiest way to drain a wet/ flooded crankcase? I've hear quite a few people mention it but no specific instructions.
  17. 2stroketech

    2stroketech New Member

    sounds like you have a bad coil. I have seen coils that will spark when the plug is out of the cylinder but will not spark under compression. Also have seen coils work well until they heat up and then they quit.

    Try a new coil and see if it fixes your problem.
  18. Bryan Smith

    Bryan Smith Member

    I've seen spark plugs do the same thing. Good spark until put in the cylinder.
  19. duivendyk

    duivendyk Guest

    It's not the spark plug but the spark voltage, f the plug does not fire in open air with TWICE the gap (0.040 +) it's not likely to fire under compression at cranking speed.At speed the engine can keep running because the spark voltage is higher but once you shut it off,it won't start up again.I think a lot of CD units fail due to moisture penetration,which causes the HT transformer to gradually fail.The connection to the plug wire is the weak point.(RTV !! )Mount it with all leads pointing down& to the rear and seal with RTV.Once moisture gets in it will never ever get out again.The reason coils fail is that water has a very high dielectric constant (81).this means that the electrical field is concentrated in the smaller gaps between winding layers.The insulation starts to break down progressively& conductive paths become established (tracking) reducing the spark output.
  20. If the magneto magnet was put on backwards, it will not run!

    See the attached graphic. IT shows the orientation of the magnet at TDC.


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