major problems engine not starting

Discussion in '2-Stroke Engines' started by hatmon, May 19, 2011.

  1. hatmon

    hatmon New Member

    alright, it has spark, the original gnt spark plug and its getting a good strong spark, ive tried 2 different cdi's neither could start it, i have taken it into my tech teachers at school, where they run chainsaw/lawn mower repairs and work on motorcycles outside of school, the magneto cover was removed the key is in place, it is taking in gas, and gas has been poured down the spark plug hole, compression checks at 90-95 psi we have tryed to start it over 50+ times using a power drill to turn the engine over with the clutch removed and getting alot of putting, but NOT A SINGLE KICK

    they have opened the engine up, before i brought the entire bike in, they looked at it and said it looked ok, but did not look into it that well, they said they have never had an engine act like this before and don't know what could be wrong with it and are running out of options, the engine is getting plenty of gas and air, good compression, good spark, what could be causing the engine to not even kick over once the gas is not even igniting, ive tried ether on it myself trying to start it, and will be bringing ether in to try and start it tomorrow with a few new spark-plugs, but if that doesn't work their about to call the motor dead so i need to know what could be wrong inside of the engine, that they wouldn't notice it in the 10-15 minutes they spent looking at the inside the first time that had it partway apart the engine has about a total of 70 miles on it total, if not less, bought from luckyearlybird on ebay for about 135$ with shipping, i am needing options badly on how i could possibly get this motor to start or at least get it to kick over a couple times to give me some hope for it, heck if i could get it to kick over once it would be a start! all answers greatly appreciated, thanks!

  2. Oddzball

    Oddzball Member


    Isnt that like BoygoFast's alt?

    Anyway. you had the exhaust on it correctly? Thats important as well. No air leaks from exhaust or intake. You cant always "see" them either. Best way to make sure is to coat the intake tube in a high temp silicone before putting carb on it.

    As for the exhaust. Toss out that POS gasket they give you and get some exhaust gasket making material. Make a new gasket.

    Oh and what color was you sparkplug. Black, brown, tan or white?
  3. Scottybotty

    Scottybotty New Member

    If spark isnt the problem, I would start looking to see if its getting fuel. It could be something as simple as a stuck float or an issue in the needle valve. Along these lines, I would ensure the carb is free of debris and crud that might clog up the jet. Ensure the air filter is clean and the engine can get good air intake. From the sounds of it, I wouldnt be surprised if the problems lays in the carburator. Good Luck.
  4. goodtime65

    goodtime65 Member

    Try switching the wires going to your coil. If you have spark and everything else it could that your spark is off 180 degrees. This can happen if the magnet is not put on properly
  5. motorpsycho

    motorpsycho Active Member

    timing possibly off 180 degrees, or maybe the choke is closed.
    hey, you never know....anything is possible.
    maybe the float level is set too high causing gas to flood over into the engine?
    maybe the main jet fell out of the carb (which seems to be kind of common).
    a bad spark plug wire will give you spark, but it may not be enough to ignite the fuel (same with the spark plug).
    the white wire could be hooked to something (like a light) which will rob power from the magneto, not allowing enough power to the cdi to give a good enough spark to ignite the air/fuel mixture.
    when trying to start it with a drill....are you spinning the motor the right way?
    so many things to look at....
  6. Lazieboy

    Lazieboy Member

  7. hatmon

    hatmon New Member

    i do belive luckyearlybird is boygofast's alt account, there appears to be no discoloration on the sparkplug, it seems to be like new still, no gas is ignighting to change its color, it cant really be a problem in the carb since gas and ether has been poured down the cilinders and wont even kick, what could be wrong inside of the motor itself that would stop it from even kicking once.

    have spinned the motor both ways with the drill, no differnce either way, ive tryed 2 differnt cdi's neither of them seem to make a differnce, i put my pinky into the splug wire hole and watched some pretty hard sparks fly from my pointer finger to the head of the engine from up to an inch away sparks still jumping, the white wire is not touching anything at all, and the kill switch is disconnected.

    i will try switching wires to my coil later today and see if it makes any differnce, but other than that what are my other options?
    Last edited: May 20, 2011
  8. rustycase

    rustycase Banned

    The beauty of a 2 cycle engine is that there are only so many things going on, they are easy to diagnose and repair.
    Compression, fuel mix, ignition.

    Among the probs I've encountered with 2 strokes is the crankshaft seals in the case affecting the fuel/air mix.

    Squirt some 30wt oil at those seals, from the outside, for a temp fix, to diagnose...
    Or pack a bit of wheel bearing grease at that location for testing.

    Usually the leaky seals will not prevent an engine from starting, but just cause lower rpm speed to be basically uncontrollable and erratic. REALLY bad seals will cause the engine to run lean and burn a piston.

    That said, from my experience, it's usually ignition problems that baffle most people.

    Good luck
  9. hatmon

    hatmon New Member

    started breakdown, the top of the piston head is completely black which i assume to not be good, but it doesn't look like it should stop it from starting, and under the black of the top of the piston, there is some yellow/orangeish discoloring which again shouldn't stop it from starting, will break into the crankshaft area tomorrow i guess
  10. Oddzball

    Oddzball Member

    Eh the lack is fine. That just what happens when you burn two stroke. If the piston turns freely it should start, as i assume its not seized.

    Get a new CDI, 10 bucks. Ill bet that will help.
  11. motorpsycho

    motorpsycho Active Member

    black on the top of the piston is just carbon build up and is normal.
    the only moving parts inside a 2 stroke (aside from the gears to the clutch, the clutch itself and the magneto), is the crank shaft, connecting rod and piston, there are no valves in one of these engines.
    sometimes you will have a cdi / magneto that will appear to be give you plenty of spark with the plug removed, but them when the plug is in the engine and under compression, the spark is not enough to ignite the fuel.
    My guess is that it's an ignition problem.