Engine Trouble Ran OK for a while, then died under way... Flying Horse 66cc

Discussion in '2-Stroke Engines' started by CheezballFH, May 6, 2013.

  1. CheezballFH

    CheezballFH New Member


    I was just starting to think that my gasbike was pretty reliable; it's been running for about 3 months now (I bought it from the guy who built and was riding it up until a couple of weeks ago). I have put only about 45 miles on it, and performance has been great, everything I hoped for. But today I was on my way home from the post office and it died on me going up a hill.

    Fuel was pouring out of the carburetor (in back) all over the tranny housing, but I think that is what usually happens if it's warmed up and the engine's not sucking fuel: it just dribbles out. I shut the valve off every time I stop the engine. Is this normal? Or does this mean a carb malf which might account for the failure?

    So. Umm. I have only had this thing a couple of weeks and now it's dead and I'm not sure where to start with diagnosis (newbie here). I don't even have the original FH manual (will a Skyhawk manual do? I have a good one of those).

    Is there a checklist from most to least likely of "reasons for dying while in operation"?

    Yes, I was fueled up :) The mix was about 30:1 using high-grade synthetic 2-stroke oil, which has been working fine so far. There was no lack of power up until the moment when it coughed and died. There was no spectacular cloud of evil-smelling smoke, no drama, no scary mechanical disaster sound effects, just a sudden slowdown and a quiet death. The block was not unusually hot (but it is an unusually hot day today if that is relevant). The choke was all the way off.

    This is probably fixable, but as I say I am new to these engines and not sure what the checklist is for troubleshooting. I'll be digging into the skyhawk manual I downloaded when I got the bike, but comments from FH owners and hackers might be very useful in case there are differences.

    darn, I was just getting to like the new toy :)

  2. Skyliner70cc

    Skyliner70cc Active Member

    Gonna be rough on you newbie and I'm not going to apologize for it. What will you do if you are 20-30 miles form home riding on the off-beaten path? You need to know how these things work so you can fix them yourself if you get in a bind away from home and out of cell phone range.

    What troubleshooting did you do? Did you pull the carb and take it apart to see what happened? If you don't know how, suggest you get a pedal bike and leave the big boy toys for those who know which end of a screw driver to pick up. Fuel leaking is never normal.

    In the time it took for you to boot your computer, log into the website, and ask your question, you could have solved and repaired the problem yourself.

    Or, you could have done a search on this form and researched the problem yourself.

    http://www.motoredbikes.com/showthr...ve-learned-from-many-builds-great-newbie-read I'm biased, but this is a great place for you to start.

    BASED ON WHAT YOU ARE SAYING, MY TIPS #6 STATES to loctite the main jet. Your symptoms are similar to main jet falling off causing fuel overflow and engine not running. If that's not it, dig deeper....all an engine needs to run is compression, spark, air, and fuel. Its real simple.

    DOn't worry about not knowing how to take something apart. Its easy, just put something back together the way you took it apart and while taking something apart, look for something amiss. If you get stuck on taking something apart, that's ok and a perfect time to come here for help.

    Good luck.
  3. V 35

    V 35 Member

    Flying Horse Carb trouble

    Since the carbs are so cheap, I'd recommend getting another carb, and using your old one for parts, or to further study, repair, and use as spare. I recommend a spare Mag coil, and a spare CDI box, along with a spare carb. Now you've got the bases covered, swap in your * new * parts, tag the used ones OK, a tested good part beats a new, but untested one, when trouble shooting.
  4. Skyliner70cc

    Skyliner70cc Active Member

    I may be an azzhole, but for god's sake, don't listen to people telling you to waste your money.

    IF YOU WANT A NEW CARB, PM ME AND I WILL SEND YOU TWO CARBS FOR FREE! I have dozens of the things lying around. I don't want you to throw new parts at your issue unless you have to and if you have to, contact me. I have tons of spare engine parts that will cost you nothing to get if you need them.

    The simplicity of these carbs is why they are cheap. Their simplicity is the reason why they are so easy to repair and wasting you money on a new one doesn't help you learn to diagnos and repair the HT engine.

    You could easily have a float tangs not correctly set so you flood your bowl or what I said about main jet falling off because it wasn't screwed tight and loctited.
    Last edited: May 6, 2013
  5. crassius

    crassius Well-Known Member

    sounds like it could be as simple as a piece of crap stuck on the float needle - clean it, check float level, get a fuel filter
  6. rawly old

    rawly old Member

    Spend the extra bucks & get a reliable Japanese engine.