it refuses to start

Discussion in '2-Stroke Engines' started by murduk0420, Mar 2, 2010.

  1. murduk0420

    murduk0420 New Member

    I checked the spark plug and found we have spark, dumped a little gas down the spark plug hole, tightened the idle screw and then loosened it 3 1/2 turns to get the idle right, checked the throttle assembly and works good and I even installed a pull start for it to make starting it easier and it won't even turn over. I tried it with the choke on (up) and with the choke off (down) all you hear is the cylinder going up and down Help please. :sweatdrop:
     

  2. Hajuu

    Hajuu Member

    Doesn't really seem like pouring fuel into the cylinder is a good idea.. If it's not getting fuel, then you need to fix that..

    The idle screw will only affect how it runs when er.. idling.

    You will really need to be more descriptive if anyone more experienced here is even going to attempt to help you..

    What kind of engine is it?

    What kind of carb have you got?

    er.. I can't think of any additional details, because i'm still a newbie myself. But anything you think of that could be useful.
     
  3. murduk0420

    murduk0420 New Member

    facts

    66cc-80cc engine standard carb bought it on ebay from boygofast
     
  4. motorpsycho

    motorpsycho Active Member

    ok, first off...if you say that it won't turn over, to most people that means that the engine is locked up. but you are saying that it spins over when you are trying to start it because you can hear the piston going up & down. (turning over) if it will not run, that would be described as it not wanting to fire.
    pouring gas in the spark plug hole can cause 2 problems. 1. it will foul your plug and make it so it does not spark. 2. if you pour too much gas into the cylinder, with no spark you risk hydrolocking the engine, but it would take an aweful lot of gas for that to happen.
    you have spark, but do you know if you have fuel flow into and out of the carb?
    if your carb has a small white plastic "T" on it, in line with the fuel line...it's a second on/off valve for the gas. make sure that the "T" is in line with the fuel line and it will be open.
    if you have spark, then your wiring should be ok.
    get some starting fluid, and spray a TINY amount into the opening of the carb and try to start it. only use a tiny amount because there is no lubrication (oil) in starting fluid. just use enough to see if the engine will fire.
    If it fires...then you have no fuel flowing into or out of the carb.
    It's possible that your float could be stuck in the up position causing the needle & seat to be closed, not letting gas into the carb.
    if this is the case, you will have to take the float bowl off the bottom of the carb and check to see if the float is stuck. this happens quite often so it isn't uncommon and it's simple to fix.
    if the float is stuck, chances are just by taking the float bowl off, and moving the float up & down with your finger will free it up.
     
    Last edited: Mar 3, 2010
  5. AussieSteve

    AussieSteve Active Member

    With a stuck float or needle and seat, usually a tap on the side of the float bowl with a screwdriver handle will free things up.
    (Same goes for that odd time when it sticks open, flooding the carb and overflowing.)

    Try one attempt with the choke on, then one with it off. Repeat if needed. These things love that procedure.

    As motorpsycho said, 'turning over' is just that - turning over but not necessarily 'firing'.
    'Firing' is what you're looking for.
     
  6. motorpsycho

    motorpsycho Active Member

    yes, a few taps on the side of the float bowl should fix it if the float is stuck.
    but if that doesn't do it, the best thing would be to remove the float bowl and look inside to see what's going on in there.
    does your carb have the primer button (on the left side, top of the float bowl)?
    if you have that primer button, push it in a few times. the primer button will move the float up & down and allow more fuel to flow. (it will flood the carb with gas)
    I'm not sure if all of these carbs have the primer buttons on them.
    My friends 80 c.c. that he got from b.g.f. has the primer button on it, so i assume that yours may be the same.
    [​IMG]
     
    Last edited: Mar 3, 2010
  7. AussieSteve

    AussieSteve Active Member

    Yep, no argument there.
    I actually only thought to mention it because it happened to me the other day, for the first time with this carb - float stuck down, so when I turned the tap on, fuel ran everywhere. One light tap and fixed. If you can get away with it, much quicker than pulling down the carb.

    Having said that, I just thought I'd better add that it's a good idea to pull the carb apart for an eyeball before first run anyway.
    It's not uncommon to find the main jet and/or slide needle jet loose and floating around in the float bowl.
    Also, the carb usually doesn't seal well to the end of the inlet tube. It's worth using an 'O' ring or some sealant. I used to use a smear of Permatex non-hardening sealant, but now have an 'O' ring embedded in a groove in the inlet tube.
     
    Last edited: Mar 3, 2010
  8. Hajuu

    Hajuu Member

    Wow, you guys are thorough, nice work.
     
  9. murduk0420

    murduk0420 New Member

    update, still not firing. yes it has a primer button, I took the float bowl off and there was a white plastic donut like thing and a little lever above it that freely went up and down pretty easy and metal rod running down the middle and it has gas in it when I took it off, not alot but a little (fuel was shut off by the metal switch near tank) line shows plenty of fuel getting thru to carb. I took aussies advise also and used black silicone gasket sealent to seal the carberator to the engine (being carefull no to get any in the tube that leads to engine).I can't find a white T shaped valve any pics of this would be helpful and I completely redid the whote throttle assembly to make sure pin and spring were right. I haven't used starter fluid yet but hopefully tomorrow. But engine is still not firing. PS thanks for the help so far, it's apreciated
     
  10. murduk0420

    murduk0420 New Member

    that picture looks just like my carb
     
  11. murduk0420

    murduk0420 New Member

    and brand new spark plug
     
  12. AussieSteve

    AussieSteve Active Member

    And mine. Most don't have the extra fuel tap on the side of the carb.

    Good description of the steps you've taken, incidentally.

    Things sound to be basically OK with the carb. It might possibly be too rich to start, though. If it was too lean, it would probably start with the choke on.

    You could try it, briefly, without the air cleaner. That will make the mixture slightly leaner and might help it start, for diagnostic purposes, if it is too rich.

    Otherwise, I'd be taking another look at the electrics, if I were you.
    You said it had spark. I assume that you tested by laying the plug on the head and turning the motor over.
    Was it a nice blue spark?
    What spark plug are you using? If you're using the supplied plug, throw it in the bin immediately and buy an NGK B6HS or B5HS, then try again.

    Let us know how you go.
     
  13. murduk0420

    murduk0420 New Member

    and brand new sparkb plug also
     
  14. murduk0420

    murduk0420 New Member

    grand master 4118c second plug ive bought
     
  15. murduk0420

    murduk0420 New Member

    and I actually made the rich light, thought it must be like a chain saw and if Ihad too I could add a little more
     
  16. goodtime65

    goodtime65 Member

    If everything checks out than I would try removing the magnet off of the crank and flip it over. If the magnet is on wrong than it will get spark but at the wrong time
     
  17. motorpsycho

    motorpsycho Active Member


    good thinking there, the mag. could be off 180 degrees.

    but man, i really don't have any more ideas as to why it won't run.
    spark and fuel are present (the spark may be at the wrong time as indicated above) the only things left are air and compression.
    the thing should at least attempt to start assuming that the timing is not off 180 degrees.
     
  18. Hajuu

    Hajuu Member

    Consequentially Steve, i've heard a lot of people saying that 'if your using the one that comes with your kit throw it out immediately' kind of thing, but mine came with a NGK B6HS in the kit.

    Is that uncommon?
     
  19. murduk0420

    murduk0420 New Member

    well after putting starting fluid in it and checking magnet we discovered that the round thing the magnet surrounds is burnt and beat uplooking, the magnet had several metal shavings and several pieces fallen outof center disk and oddly a small plastic piece rattling around in there.
     
  20. Hajuu

    Hajuu Member

    haha, dodgy. You say it came like that?
     
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