Help engine does not engage

Discussion in 'Motorized Bicycle General Discussion' started by roozbeh, Jul 3, 2012.

  1. roozbeh

    roozbeh New Member

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    2-stroke engine, hard to start up, I changed the spark plug. And still...

    This is what happens when I try to start it: So I get some speed then release the clutch to engage the engine. However, right after I release the clutch the bike slows down as if I pulled the brakes. So the engine does not start up. (P.S. IT WAS NOT LIKE THIS WHEN I FIRST BOUGHT IT) and thanks for any help!
     
  2. nightcruiser

    nightcruiser New Member

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    Assuming since you have run the motor previously you can tell if the motor is turning over or not? That is the first thing you need to nail down, is the motor turning over when you dump the clutch? If not then you probably have a clutch problem.
    If the motor is turning over but not starting then you have a whole other set of things to check. First thing I usually ask of people when their motor suddenly doesn't start is "did you turn the fuel valve off when it was parked", I read about people flooding out their motors pretty bad when the fuel valve is left open on some motors (proper float function should prevent this but...). If you have a flood condition, in addition to cleaning/changing the plug you should roll the bike around a bit with the spark plug removed and clutch released, the motor will turn over and blow air and any fuel in the cylinder out through the spark plug hole. (make sure there is no SPARK or flame around that will ignite the fuel that may come out, also make sure no debris is drawn in the spark plug hole) Often times a no start bike will start right up after doing this.
    You should also check that the air filter is not clogged up with dirt or oil residue, see if she fires up with the air filter removed? Check the spark plug boot to see that the electrical contact is still intact. Disconnect the kill switch to make sure it isn't killing the ignition. Make sure fuel is flowing freely from the tank. All the basic stuff, beyond that you will have to give some more info to get better advice.
    Also, before the rings seat on a brand new motor the compression can be kinda low (motor turns over very easily), once the rings seat the compression goes up and it is much harder to get the motor to turn over. Perhaps you are just feeling the additional compression and need to build more momentum to overcome it than when the motor was brand new?
     
  3. roozbeh

    roozbeh New Member

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    The motor turns but ussualy 9/10 times it will not start. Furthermore, I fallowed what you told me "If you have a flood condition, in addition to cleaning/changing the plug you should roll the bike around a bit with the spark plug removed and clutch released, the motor will turn over and blow air and any fuel in the cylinder out through the spark plug hole. (make sure there is no SPARK or flame around that will ignite the fuel that may come out, also make sure no debris is drawn in the spark plug hole) Often times a no start bike will start right up after doing this." I took it out for 20 minutes without spark plug.
    And Now The Motor Will Not Start At All!! : ( )

    PLEASE HELP :'(
     
  4. nightcruiser

    nightcruiser New Member

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    Well, I don't know how you went from "roll the bike around a bit" to taking it out for 20 minute ride? That does not compute! To clear a flood you only need to "roll the bike around a bit" and let the motor turn over a handful of times to let that fuel out. Then you put the plug back in and start her up...
    2-stroke motors need to be lubed by the oil in the fuel, if there is not fuel/oil flowing you should not turn the motor over for extended periods. For instance, even coasting down a hill, you should either pull in the clutch to disengage the motor or rev the throttle to make the engine combustion rate match the speed you are traveling. If you let off the throttle and let gravity pull the bike and turn the motor over you are not properly lubricating the motor for that period. Keep in mind that a 2-stroke has no reservoir of oil to keep the motor lubricated. Particularly when a motor is new you need to keep it lubricated, thats why you use more oil in a break in fuel mix for the first couple hundred miles....
    Now back to the situation at hand, I am still lacking good info to help you out. There is a document floating around here that has a basic check list for a no start condition, seek it out by searching the forum or perhaps someone that knows the link will post it here.
    Basically you need air, fuel, spark and compression to run. You haven't let on exactly what you have checked. Have you....?

    Disconnect the kill switch
    Check the electrical contact in the spark plug boot
    Check the air filter
    Check that fuel is flowing in the fuel line

    Those are the very basic checks to do, from there you can....

    Check if there is spark on the plug?
    Try an NGK BP6HS plug, the kit plugs are crap

    Does the motor feel like it has good compression?

    There are lots of other things you can check that go beyond these basics, but I don't want to waste time typing about a situation I dont know exists... So check some stuff and post back more info... including what motor and carburetor you have... if you're not sure post a picture... and search the forum and read the advice the 1,000+ other riders received when they posted about their no start condition....
    Basically you are going to have to learn a bit about how a 2-stroke motor works to keep this thing running, the good news is this motor is about as simple as it gets, and this forum has lots of smart people that are willing to help you learn, so dig in and read and wrench and post your questions as you move along....
     
    #4 nightcruiser, Jul 3, 2012
    Last edited: Jul 3, 2012
  5. roozbeh

    roozbeh New Member

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    Before i continue with the problem I want to say thanks so much for your help!
    So I did basic checks, fuel goes down, opens carb to see if anything blocking fuel path, I checked the electrical lines and all were perfect! Now I also checked the throttle to see if it opens the gas valve and it works fine, plus I changed the spark plug with a brand new one and still no luck! FML

    I am about 99% sure the motor might be missing a few chromosomes(kidding :/)
     
  6. roozbeh

    roozbeh New Member

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    F*** man wdf happend I ran it without a spark plug now it wont f***ing start... PLEASE somebody like 2door help! </3
     
  7. nightcruiser

    nightcruiser New Member

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    Did you disconnect the KILL switch? and make sure the WHITE WIRE is isolated and not touching anything?
    When you pull the plug after attempting to start and failing how does it look? Wet? Dry? Does the new plug you put in there look like it fired at all? You could check that the woodruff key is still in the magneto and the magneto is in the correct position....

    This is the link from AI.Fisherman that I was referring to which covers all the basic stuff:

    https://docs.google.com/document/d/1aBeJuoS--VQWwXysc07rpscTUbPzgc93xjiQBgsyFjc/edit?pli=1
     
  8. roozbeh

    roozbeh New Member

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    Okay so the spark plug gets a tiny bit grey but not oily or wet, and when I wipe it off with a cloth it looks almost the same as it was brand new. The kill switch connectiongs all removed no luck, the fuel goes to the carb check, the clutch is engaging the engine check, tried with a loose spark plug no luck, tried with a tight spark plug no luck, checked exhaust and everything looked fine, tried to run with carb leaver up, middle, and down and no luck.





    One FAR guess of what I think might be the problem:
    -I used 16:1 gas/oil ratio for break in so I think that was to much oil for engine causing engine to be so greasy it cannot start now. And when I tryed to run without the spark plug it completly destroyed the system?

    P.S. THIS IS HONESTLY MAKING ME WANT TO COOK THE ENGINE IN AN OVEN, stab it with a knife, kick it, hit it with a baseball bat, eletrecute it, and I will be happy! : ((
     
  9. roozbeh

    roozbeh New Member

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    night cruiser I appreciate the effort you have been help full and it is not your fault, but I honestly cannot think of anything in the world that could make the engine run. I think my asian lady just does not like me </3
    RIP engine >:l
     
  10. nightcruiser

    nightcruiser New Member

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    Well, we need to get a grip on what is right and wrong, and what is good for your motor or not... You should never try to run the motor with a loose plug, that is not a good idea. You should also not turn over the motor for excessive periods without it running cause it needs to be lubricated.
    That said, as long as you didn't blow the spark plug out of the whole and rip out the threads from the head the loose plug didn't cause a problem, as long as you still have compression when you tightened up the spark plug the running around without the plug installed didn't cause the problem either. The 16:1 ratio fuel is a bit heavy on oil but that will not ruin a motor either. If when you install the plug tight you have compression then no harm no foul man...
    Still you are back at step zero, a no start motor. You CAN get this thing running, you just need to work at it a bit more....
    You really need to tell me what kind of motor you have, specially WHAT CARB, I haven't seen that info posted yet? The carbs can be quite different, so which one you have is important to know.
    From your last post about your spark plug I get to thinking you have a no fuel situation, because after trying to start her up with no luck you would think the plug would be a bit wet with fuel? If your rag is coming up clean when you wipe the plug then maybe you have a clogged up carb??? I would check the needle valve and main jet to make sure they aren't clogged. Starting fluid is not generally recommended for use on a two stroke (cause it doesn't provide lubrication) but a tiny squirt in the spark plug hole before you install the plug, or a shot down the throat of the carb (with air filter off) should deliver enough fuel to get her to POP a few times if fuel delivery is your problem. If a shot of starting fluid makes her pop then look more closely at the carb and fuel delivery system. If you get no pop with a shot of starting fluid then I would look more closely at the ignition. You could have two bad plugs (the kit plugs are crap) you could also have a bad CDI, or a bad magneto (or magneto with bad solder joints). To check the spark you can pull the plug, put the plug wire back on it, then lean bottom of the plug against the block to ground it and turn over the motor a FEW times and look for spark on the plug. (keep the plug away from the spark plug hole to be sure it doesnt ignite fuel if any comes out)
    On the compression, when you install the plug (tightened properly) the motor should offer resistance to turning over, much more than it does when the plug is out. If this is the case then your compression is probably OK. If the compression is weak then perhaps a head bolt(s) is loose, or you blew a head gasket? Again, have no idea if this is your problem not being able to feel the compression myself, you've gotta judge that on your own.
    Again, post back more info on your motor and results from some of these tests and someone should be able to help you get her going.
    By the way, when the motor died was there any event attached to it? A noise, backfire etc?
     
    #10 nightcruiser, Jul 4, 2012
    Last edited: Jul 4, 2012
  11. roozbeh

    roozbeh New Member

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    OMG YOUR A genius! I <3 you, I did what you told me and found the problem.
    NO KIDDING I OWE YOU ONE THANKS SO MUCHHHHHHHHH! I would have never thought of that, thanks again man! god bless you! :D
     
  12. nightcruiser

    nightcruiser New Member

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    I'm really happy you got your motor running, and I'm sure you learned a lot in the process that will help you keep her running...
    I threw out quite a few possibilities to you, if you don't mind could you tell me what ended up to be your problem so I can learn from the experience as well?
     

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