Problem here

Discussion in '2-Stroke Engines' started by systo520, Sep 22, 2010.

  1. systo520

    systo520 New Member

    OK so heres what happened, i took my bike down the road about a mile, the whole way there it worked fine till aboutt 2 blocks away it sounded like i heard a loud pop. dont know where it was from, but the motor still worked the next 2 blocks. i have a 50 cc motor btw if it makes a difference. i hop on it to ride home and decide i wanna pedal home, so i pedaled most the way home, decided to release the clutch, it kicked the motor on, tried to twist the throttle but gave no response the motor choked out cuz it wasnt getting gas it seems like, now before i left i filled the bike with gas, the gas that was given to me at time of purchase (2 days ago), fuel was on, only thing i can think is it was bad gas or something, but it says it was a gas oil mix in the can so i just poured it in. is this a bad gas problem or something else? Like i said the motor kicks on but dies after a few seconds because its not getting the gas, at least thats what it seems like to me but im a total newb when it comes to these. thank you

  2. systo520

    systo520 New Member

    anyone have any advice??
  3. Remove the gas from the tank and discard it, clean the tank thoroughly, replace the fuel filter, if it doesn't have a fuel filter get one and install it between the tank and the carb, disassemble the carb and clean it thoroughly, reassemble the carb, install the carb to the engine with an O-ring of the correct size to prevent air leaks, throw out any gas you have and buy fresh gas, mix with a quality 2 cycle oil (find the best oils to use by searching this site) in the correct ratio for your engine, remove gas line at the carb and open the petcock to make sure you have a good flow to the carb, and finally, clean or replace the spark plug. Never use old gas. Never use gas-oil premix you haven't mixed to the correct ratio yourself. Luck.
  4. systo520

    systo520 New Member

    thanks, so it does definately sound like a bad gas problem?
  5. It sounds like a blockage in the tank, gas line, or carb. Dirt or rust in the tank/gas will cause blockage in any small orifice or tube it tries to flow through. Make it clean, then keep it clean. Old gas can be a problem with any engine, for 2 stroke gas-oil mix even more so, and these cheap Chinese engines especially.
  6. motorpsycho

    motorpsycho Active Member

    hopefully that was gas with 2 stroke oil that you put in it, and not straight gas.
    the pop noise could have been a backfire out of the exhaust from the engine leaning out.(too much air, and not enough gas going into the cylinder)
    it could have leaned out if it ran out of gas (no gas flowing into the carberator). but if the carb. was not getting any gas from a blockage, then it should not have quit running after you heard the pop and it never should have ran at all on your second attempt to start it. you said that it restarted when you tried it the second time but you had no throttle response. if it was not getting gas the engine should have never started on the second try. IF it was straight gas that you put in it, you might have severly damaged the piston rings, (and the bearings for that matter) which would cause a loss in compression, which would cause what you described. no throttle response i.e. no power. the engine still may run, but it may run poorly and have little to no power. sometimes a 2 stroke will just lock up when you run straight gas in it, and sometimes they will continue to try and run if the bearings are not damaged too bad. but eventually, it will lock up from no lubrication. I'm not saying that this is what happened, but it's a very good possibility.
    IF in fact it was straight gas that you put in it, with no 2 stroke oil, you may have major internal engine damage.
    if it was straight gas with no oil, then you just ran your engine with no lubrication AT ALL...same as draining the oil out of your car engine and taking it for a drive.
    Last edited: Sep 22, 2010
  7. HeadSmess

    HeadSmess Well-Known Member

    pops to me sound electrical in nature... usually combined with a leaky exhaust manifold...

    the loss of power then sounds like erratic sparks...

    the clean/replace plug advice sounded the best.

    how have you got it wired?

    *looks suspiciously at the white wire*


    wait for it....

    main jets blocked.

    take a peek inside the carb bowl...only two screws :)
  8. motorpsycho

    motorpsycho Active Member

    if the main jet was blocked then no fuel would get into the engine...hence, it wouldn't have started on the second try like he said it did.
    it could be electrical as others have said,,,and it could be an intermittent problem (a wire with a loose connection or a wire touching something and grounding out).
    BUT...that would not explain the no throttle response that he mentioned AFTER the engine was running for the second time.
    Last edited: Sep 23, 2010
  9. HeadSmess

    HeadSmess Well-Known Member

    semi blocked main jet?

    either a flake of paint or gunk or just "shellac" deposits from lousy storage methods... fuel filters are good :)

    lets enough in to start, idle, crack the throttle... then die :)

    another problem im getting lately which might be it...

    my float needle is actually jamming in the seat...sometimes its fine, sometimes it starts, runs for a few seconds, dies(as the bowl empties)...until i stick some wire down the brass inlet barb and free it up again....
  10. Stan4d

    Stan4d New Member

  11. RdKryton

    RdKryton Active Member

    Many good ideas to solve your problem have been mentioned but you need to start at the beginning. Going about it in a helter skelter manor will just confuse the issue. This is how I go about trying to solve a problem like what you are experiencing. It sounds like you are getting some fuel but not nearly enough so please try these steps to make sure you are getting enough fuel. I believe it is a fuel problem not a spark issue because it starts but will not stay running.
    1. Pull the fuel line off the carb and turn the fuel petcock on to see if there is a good fuel flow. If not, correct this issue before doing anything else. Most of the gas tanks have a small strainer on the petcock just inside the tank. Remover the tank and drain the fuel. remove the petcock on the bottom of the tank and remove the strainer. I don't put it back because they clog so easily. While you have the tank off the bike put a small amount of clean gas in the tank and swirl it around to clean the tank. Reinstall the petcock. Now remove and replace the inline fuel filter from the fuel line. If you don't have one get one and install it now. You have to have one now that the strainer has been removed from the petcock. After you have this reassembled add some fresh gas and oil mix to the tank. See if you now have good flow to the carb when you turn the fuel petcock on. It should be flowing good now so connect the gas line to the carb and give it a try.
    2. If the symptoms remain the the fuel blockage is in the carb and it must be cleaned out. Remove the carb and clean it out. I take the bowl off and blow out all the passages with carb cleaner. Be very careful so you don't loose any parts. Reassemble and try to start the engine. It should fire up and run if the problem was just a fuel problem.
    BTW I always replace the spark plug because 2 stroke engines are hard on them. They may look fine but...
    If after all this you still have the problem then it must be electrical. These steps have always worked for me. By doing these steps you can rule out a fuel problem and now move on to the electrical side.
    Good luck

    Last edited: Sep 27, 2010