Engine Won't Run... I havn't found an answer yet...

Discussion in '2-Stroke Engines' started by agentjosh77, Sep 23, 2009.

  1. agentjosh77

    agentjosh77 Member

    Well... almost everything is good. The darn thing is just running terrible!

    It has absolutely no bottom end.

    It is sputtering like crazy.

    Any slight incline and it just dies.

    It will not idle at all.

    I will be going down the road and it will sputter out and die on me.

    Here are some of the facts:

    I have checked the bowl of the carb and the jet isn't lose. The only thing that is loose in it was the float like it should be.

    I have the idle screw turned all the way in and backed out 1 and a 1/4 turn.

    I prime the engine 3-4 pumps.

    I get to pedaling and get going to the road, release clutch and it fires away.

    I adjust the choke half then to off (down, I am assuming this is correct).

    Then the problems ensue after I have ridden for about 20-30 seconds.

    I checked my spark plug and it is pretty wet.

    Anyone have any suggestions???

    Thank you everyone,

  2. give me vtec

    give me vtec Active Member

    I would run the choke fully open... what ratio of gas/oil are you using???
  3. Shadeslay

    Shadeslay Member

    I'm not sure what you are mixing at, but 20:1 is good enough for break in.
    Last edited: Sep 23, 2009
  4. agentjosh77

    agentjosh77 Member

    Thanks for the replies,

    I am started running it full open, only a slight improvement was found.

    I am using a 16:1 for break in.

    When I get a chance to set down with the bike again I will go through the checklist Shadeslay.

    Thanks guys, I will be posting with a update asap.
  5. give me vtec

    give me vtec Active Member

    do you live at an excessively high altitude???
  6. agentjosh77

    agentjosh77 Member

    Ha, no I live on the flat Oklahoma plains. I will post some pictures of my build for anyone that wants to look it over to see if they spot anything glaringly wrong.

    Thanks again,
  7. bigdan

    bigdan Member

    Are you getting good spark. This is a little tricky but It works to test for spark.

    try taking the spark plug out of the engine but leave the boot and wire connected and then while pedaling down the road hold the electrode end of the spark plug against the side of the engine (or some place that is electrically grounded if your engine is painted) and engage the clutch. The engine should turn over and and you should see a spark. I haven't tried it but you might be able to use a timing light instead of pulling the plug.
  8. Hawaii_Ed

    Hawaii_Ed Member

    this is a new build? Could be an air leak at the carb mount, very common problem.
  9. spad4me

    spad4me Member

    Check for a clogged jet, or needle valve where the float lets the gas into the carb.
  10. GearNut

    GearNut Active Member

    If his sparkplug is pretty wet, I would not suspect a plugged fuel jet.
    Perhaps a too big of a fuel jet though.
    A float setting adjusted too high will easily cause the problems he is having.
    That was one of the first things I had to do to my first MB.
    The thing would cough, sputter snort and die every single cotton pick'n time!
    My biggest clue was gas drippin' out of the exhaust pipe after running myself ragged pedalling the darned thing in circles. Trying to start it, just to hear it start, rev up a bit, "wing-ding-ding-ding-ding", sneeze and die.
    Sometimes it would just go Wing-ding-ding-ding-*Pluah*! out the pipe and stop. Trying to throw me over the bars!
    I bent the 2 float lever arms down, away from the carburetor body, just a teeny bit to lower the fuel level in the bowl. It made a world of difference!
    Oh yeah, I had to blow out the bottom end with compressed air too. The flywheels were drowning in raw fuel! I got a good misty spray out of the sparkplug hole for a minute or two!
  11. agentjosh77

    agentjosh77 Member

    GearNut your symptoms sound identical to mine, even down to the...MB speaking now" lets see if I can thrown Josh over the handle bars when I lock up in mid ride.

    Anyways, I will go and try to bend the float arms down a tad.

    How do I blow the fuel out, I know there is going to be some build up because I have gas leaking out of the bottom of my muffler as well...

    Thank you again everyone!!!
  12. GearNut

    GearNut Active Member

    I removed the sparkplug, rolled the engine over untill the piston was at the bottom of the stroke, which is opening up the exhaust port and transfer ports in the cylinder, and removed the exhaust pipe. Then I used my air gun and carefully put it down the sparkplug hole and into one of the transfer ports. BE VERY carefull! You do not want to scratch anything in there!
    I just held the air gun open untill the fuel spraying out of the exhaust and sparkplug hole stopped and held the air on another minute to be certain all was cleared out.
  13. Always be sure to shut off your fuel while at rest. You could have an excessive amount of fuel sludge plugging up the exhaust. Also check to make sure the intake does not have a blockage from flashing. A kit i put on a guys bike would not rev and had flashing almost closing off the intake manifold. Might also want to cut some off the muffler pipe inside and check to see what slot carb setting is on..I cut mine off 1/4 up from bottom and put on 3rd slot and opened up the air cleaner lid...
  14. MikeJ

    MikeJ Member

    You write of having "absolutely no bottom end". My engine has the same characteristic. It is not until I get the RPM up to over 3200 that it does not cough or sputter or act wimpy. Not until RPM exceeds 3200 or so that the engine actually puts out some pulling power. On a stock build, that equates to about 15 mph It does not start firing on every crankshaft cycle until RPMs are up and the engine is put under stress to pull harder.

    760 miles and counting.
    Last edited: Oct 3, 2009
  15. I must be lucky i havent had any problems with mine at all,it runs great,idles great and will go 34 mph with a 44 tooth sprocket. My buddy that i ride with i always have to do something to that thing when we ride lol...i took everything apart and either blue or red locktited it even carb stuff. Put a strip of shrink wrap on end of intake and no air leaks to carb. Only thing i noticed coming lose was the kickstand that i didnt locktite but now thats taken care of . I have over 378 miles so far (knock on wood) . Id open up the air cleaner lid with a die grinder or file so it looks like a frown face so air can come straigt in,and check your muffler inside to see if its not clogging up. If so clean it out, also clean your air cleaner and rejet the carb setting slot to 3 if you cut off inside muffler pipe tube...