Petcock problem

Discussion in '2-Stroke Engines' started by Arty, Sep 5, 2016.

  1. Arty

    Arty Active Member

    After doing numerous modifications to my China Girl, including ignition, porting, piston, fuel delivery etc., I just could not get my bike to run properly. It was way too hard to start, and if you could get it to start, it would run for an unreliable period of time, begin to refuse to idle down, then usually stop, etc. etc..
    After endless hours of back-pedalling and re-checking my mods, in desperation, since I couldn't think of any other possible trouble source, I took apart the fuel petcock. - There was a tiny flake of metal embedded in the rubber seal of the petcock - and I mean small - way less than the size of a pin head. It must have been just the right size to let a small quantity of fuel through at times - and at others to block it completely - allowing the engine to run once in awhile, and leaning it out and starving it at others.
    I think the flake was probably a tiny piece of zinc from a 1/4inch galvanized elbow in my fuel line, that flaked off when I tightened the elbow I had added during the course of my modifications.
    Anyway - what a relief to finally find the problem.
    Another hard learned lesson about a rule I already knew - but ignored., - - ONLY DO ONE MOD AT A TIME.
    So - just a heads up - those fuel petcocks have really small internal passages, so any little piece of foreign material can cause a problem.
    Also, I noticed that because of the design of the petcocks that come with the China Girl kits, unless you have the Shut-off lever exactly lined up with the "OFF" marker on the petcock body, the fuel can still get past. The stops on the valve only work for the "ON" position, not the "OFF".

  2. Glad to hear you found your problem it's always a little tiny things that mess you up in a big way.
    My question to you is the term(CHINA GIRL) type of engine I have on my bike on. my profile picture which means just a generic engine. 49/50cc, that's what I had but people ask me what kind you have I say BLACK. LOL!
  3. Arty

    Arty Active Member

    My engine is a 66cc "Skyhawk GT5A" made in the "YuanDong Gas Engine Factory"- obviously made in China. I could be wrong but I think the term "China Girl" refers to pretty much any 49/66cc 2-stroke made in China.
  4. Thanks that's what I thought. I just don't like. OR WANT! To tell all my friends who drive Harley Davidson's (sounding like a puny dweeb) OH YEAH! WELL I RIDE A 49cc "CHINA-GIRL" AND IT AINT A 21 YEAR OLD HOT CHIC! LOL! Oh well some day, some day.................
  5. Arty

    Arty Active Member

    To tell the truth, I kind of like the "mystique" for lack of a better word, of riding around on an engine that costs probably less than a Harley foot-peg, and probably having more fun than the big rig rider. and I say that as a person viewing the picture from both sides, because I also own two "real" motorcycles - a Triumph, and a 4cylinder Honda.
    You can hot rod the s--t out of the little two strokes for very little money, and with a very few inexpensive tools, and if you blow it up - -hey it only costs a hundred bucks or so to buy a brand new one.
    What's not to like?