Engine Trouble Complete rebuild? New engine? Scrap metal money? lol I can pedal faster than this!

Discussion in '2-Stroke Engines' started by StrangeTechnician9, Jun 23, 2012.

  1. StrangeTechnician9

    StrangeTechnician9 New Member

    So I have a 66cc sky hawk slant head.


    Lots of gas shoots back into the air filter. I've searched and supposedly its "normal"? I have to clean the filter before each ride and I notice my performance dropping during my 20-45 min ride.

    Top speed seems to be about 12 if I don't pedal. And goes back to about 12 if I stop pedaling. Not that speedometer works or anything, but I can pedal twice as fast as this engine pushes me.

    If I cut the gas off, just before I run completely out I get great performance out of it. That's how I want it to run!

    Holding the clutch in, giving it WOT I can see gas leaking just a little from the crank case near the top of the rear mount.

    Spark plug used to be soaking wet and black. I added more gas to about 45:1 now it's dry and black. Last time I checked, apparently I didn't have it tight enough and gas/oil leaked from the plug so the outside was wet and black but the inside was dry and black.

    The small chain gear on the motor, and everything around it under the cover is getting pretty wet with gas/oil mix.

    Gasket from intake is wet.

    What I did;

    I made a boost bottle out of some random plastic containers and vacuum tube.
    Actually seems to help w/ the fuel shooting out the back problem.

    Used 1/2 a soda bottle, breather filter, and more vacuum hose to try to force more air into the carb from the stock air filter.
    If anything it just helps get more fresh air into the carb.

    Took off and wiped the magneto. Not wet at all just some metal shavings or something in there.

    Rebuilt carb.
    Float seems to be working although I wouldn't know what I'm looking for.
    I have no settings on my needle and no room to make my own notch to try giving it a higher air:fuel ratio.

    Kill switch is not hooked up because it didn't work and I don't want to mess up the low quality stock electrical system. I'll probably install a toggle switch in the black wire at some point.

    Its gotta be something not working correctly right? Everything has to be working somewhat since I have no problems starting it up or running it. It just has no power.


    1. Do I really have to take this completely apart and throw away the gaskets and use gasket maker on everything?

    2. Even the head?

    3. Could the stock CDI be causing this.

    4.What can I do to get this running perfectly?

    5. Should I wait till I get it all running perfectly before installing the NOS kit? lol

    6. Anyone know where I saw that upgraded hardware kit on the net somewhere. It had all the nuts and bolts US made to replace the stock stuff.

    Thank you all for everything you've already done by the way. I would have never even gotten this far with out this site. Your all awesome!


  2. timtooth

    timtooth Member

    you should try adjusting your float by bending your float arms. An also on the stock cdi you have to take your gold tip off your spark plug if you didnt do that already.
  3. Fabian

    Fabian Well-Known Member

    @ strangetechnician

    For normal rpm range operation, just get yourself a Rock Solid Engines, Reed Valve Kit - this will completely eliminate the mixture blowback, without the puddle of oil that drips from your air filter.
    It will also noticeably improve low and midrange rpm torque - a win/win situation.
  4. motorpsycho

    motorpsycho Active Member

    your float in the carb is set too high. the carb is flooding over, letting too much fuel into the engine, making it run way too rich.
    the reason why performance increases when you shut the gas off is because it's getting less gas and more air (lean).
    this is an easy fix!

    it is normal for a 2 stroke without a reed valve to spit a little gas out the back of the carb. but not so much that it soaks the air filter.
    your air filter should have a little oily residue on it in normal circumstances.
  5. StrangeTechnician9

    StrangeTechnician9 New Member

    Sorry for taking forever to reply. I'm having noob problems apparently. (username & password stuff)

    I adjusted the float just a tiny bit... I wasn't even sure if I had bent it at all, but I wanted to just do a little at a time to be sure I don't over do it.

    Well then engine wouldn't start at all. I open the drain on the carb and no fuel drained out. So I bent it back the other direction and then fuel steadily drains out the overflow/drain tube.

    After a few hours of bending back and forth. I finally find the right spot where fuel is allowed into the carb and it stops before hitting the overflow thing in there.

    ...Back to the original problem

    If I add more oil to my gas that should make it run leaner right? I did have more power when I was "breaking it in"

    Maybe I need to clean the exhaust? I've realized at very low RPM i have pretty good power it seems. But as soon as it gets to where I think the power should start be it stops accelerating.

    If the cranck case leaks bubbles of fuel, and air is thinner than fuel, more air should leak out of the seals than gas right? IF that is true then it would make the engine run way too rich right?

    If I break open the case and replace all the seals and gaskets on everything w/ high quality hi-temp gasket maker, it should seal up well right?
    Last edited: Jun 26, 2012
  6. StrangeTechnician9

    StrangeTechnician9 New Member

    Really? Thats it? Spark plug and float? Why didn't someone tell me to check the fuel tank? Check to make sure the wheels are on the bike?

    This is really all the advice I can get from here? I'm ready to give this ____ away... Wilmington NC. If you can get here or have it shipped from here its urs.
  7. ghz24

    ghz24 New Member

    I don't know your engine but I had a weed eater motor that spit excessive fuel into the air filter. I was surprised to find no reed valve. It turned out it was a mud wasp nest obstructing the exhaust.

    Oil to fuel ratio is different than fuel to air ( rich vs lean).
    I'd stick with the suggested ratio for oil to fuel.
  8. motorpsycho

    motorpsycho Active Member

    sounds like your crank seals are blown. Your crank case could be full of fuel from the carb flooding over, which may have blown out the seals.
    i'd run it at 32:1 if you've already broken it in. if you are in the break in stage still, i'd run it at 20:1.

    did you check to make sure you have air in the tires?
  9. StrangeTechnician9

    StrangeTechnician9 New Member

    So apparently I just need to calm down and check everything right. It could only be so many things. I think I use this thing for transportation so I need the problem to be an easy fix. Unfortunately, it seems my world isn't as perfect as I'd like it to be. So, I've learned the bus system :/.

    Fuel does leak from the crank case. In the middle of the engine. Also in the area the chain rides on the small engine sprocket. I'm going to run this with Nos when/if I get it working right. Should I get a new seal from pistonbikes, use high quality hi-temp gasket maker, or both? I was thinking both. Then sanding my head while it's appart and using both there too.

    About that air in the tires.... That might be another thread ha ha! We're good now tho. :)
  10. vermhot

    vermhot Member

    First off I think you might have the CNS carb,wish you could post a pic ,if you do I would tell you to junk it and buy a NT or a pocket bike from DAX .com . I think you need to start to read every thing you can on these things !!! That is what I did ,took my time putting it together and been riding it for a wile now !!!! There is alot of info on here just read man !!!!!!
  11. StrangeTechnician9

    StrangeTechnician9 New Member

    Took my engine completely apart...


    ^ that helped

    New problems... what is a magnet key and why does it matter?

    I'm about to just put this thing back together and I'm almost sure its not gonna work. How does it know when to send a spark?

    If anyone can tell me how to fix the problems I'm going to have after I figure out which pieces go where and throw it back together it would be much appreciated. Timing, but what else?
  12. BigBlue

    BigBlue Active Member

    Are you talking about the woodruff key? It is for the ignition timing - when to send a spark. No parts should be left over.

    Good Luck,

    AKA: BigBlue
  13. Lunardog

    Lunardog Member

    Boost bottles....NOS..... if your having this number of issues you should remove everything but the stock parts. Make it run correctly first then ad performance parts, not the other way around. Just my 2 cents.
  14. vermhot

    vermhot Member

    x2 what Lunardog said !!!!!!
  15. StrangeTechnician9

    StrangeTechnician9 New Member

  16. StrangeTechnician9

    StrangeTechnician9 New Member

    Boost bottle was to fix the problem. I've heard on here that gas/oil in the fuel filter is "normal" and the boost bottle will help to FIX that normal PROBLEM. I didn't like cleaning my air filter out every time I ride for 10 - 20 min.

    NOS... I didn't buy a engine kit to ride it stock. This is my only transportation for AT LEAST a year and a half from the time it works. I want it known that I will be running NOS when it is fixed or when I sell it and buy a new kit. I dont know enough about engines to know that a standard head gasket/ piston / piston rings. etc wont destroy my engine when I do put the NOS on.

    I've already taken the boost bottle thing off and sealed the hole in the intake. I just have a hole in the air filter now with a small vacuum hose attached to it that is bent and wire tied so if it ever runs again and the filter clogs with fuel I can just open the hose instead of running it without the filter to get home.

    Thanks though. You do have a good point. But so everyone knows. This is exactly what I am trying to do
  17. BigBlue

    BigBlue Active Member