Engine spluttering when I hit 20mph...

Discussion in 'Motorized Bicycle Trouble Shooting' started by dimentio, Feb 3, 2013.

  1. Greg58

    Greg58 Active Member

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    The air to fuel ratio entering the engine has too much gas in it, this is usually from too large of a main jet. A lot of the nt carbs run a little on the rich side. A ratio of about 14 to 1 is good, altitude can affect the mixture also.
     
    #21 Greg58, Feb 13, 2013
    Last edited: Feb 13, 2013
  2. BigBlue

    BigBlue New Member

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    Too rich? Think of your carburetor as a primitive blender - it mixes the air and fuel together. Too rich means that you have too much fuel and not enough air. If ice was air and tequila was fuel, you have too much tequila and not enough ice in the blender. Your margarita would be too slushy! Not good!

    Hose? Probably a fuel grade hose or rubberized fuel line from an auto parts store.

    Good Luck,

    Chris
    AKA: BigBlue
     
  3. nightcruiser

    nightcruiser New Member

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    When referring to the blend of air and fuel the term "too rich" means too much fuel, and "too lean" means too little fuel.
     
  4. dimentio

    dimentio New Member

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    Hm... so i need to increase the amount of air entering the carb then right? I saw some pics online of a carb with the filter turned upside down with the intake holes shaved at an angle... might try that.
     
  5. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Move the c clip up one notch to lean it out, that's what it's there for.
     
  6. BigBlue

    BigBlue New Member

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    You have to reduce the amount of fuel (tequila) or increase the amount of air (ice) to make that perfect frozen margarita!

    As bikeguy Joe stated move the C-clip one notch (add more ice). I would stay as stock possible before you add more variables to the mix. In other words, perfect the basic frozen margarita first before moving onto other fancy versions - no watermelon or peach frozen margaritas for you.

    Chris
    AKA: BigBlue
     
  7. Greg58

    Greg58 Active Member

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    A sick bike parts air filter helped one of my bikes, it flows a lot more air than the stock filter.
     
  8. 2door

    2door Moderator

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    You could try adding a shot of tequila to your fuel mix but leave out the ice, lime juice and don't add salt. It might not run any better but your exhaust will smell great while you're riding :)

    Tom
     
  9. crassius

    crassius Active Member

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    on hoses, I like clear ones so I can see gas flowing
     
  10. Groove

    Groove New Member

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    e-clip. That's what I'm talking about! Try moving it up man. One notch.
     
  11. Greg58

    Greg58 Active Member

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    I use gates or dayco fuel line with a see through filter.
     
  12. dimentio

    dimentio New Member

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    I can't seem to shake the problem. This motor i have is kinda beaten up. When I crashed my Schwinn riverside cruiser, i was able to salvage the motor from it. the motor has been thru a lot of trauma. rain, snow, i've even fallen once or twice on the genesis 29 i mounted it on. I even got swiped by a car a few weeks ago while i was parked. so i think its time for a new motor anyways. just got my RT carb in the mail yesterday. i just ordered a new motor this morning. Im just gonna wait for that and redo the bike. I also got a expansion voodoo chamber, i just need to take it to a shop to get it bent.
     
  13. nightcruiser

    nightcruiser New Member

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    Though you're motor may be beat up, didn't it run well before you changed to the new carb and intake? My guess is you need to TUNE the new carb, and you will probably have to tune the carb on the new motor too. If you want to experiment while you're waiting for your new stuff, either put your original carb back on the old motor and see if she runs better, and/or, move the float and jet (and air filter if it is different) over from the old carb to the new carb. My guess is the float setting is different on the new carb, move the float, move the setting. Or the jet could be not exactly the same size. My guess is it has more to do with the carb swap than the new intake or how beat your motor is. Good luck with your project...
     
  14. BigBlue

    BigBlue New Member

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    In my opinion, your not going to get what your looking for if you don't know how to work on these engines and understand the principles of how an engine operates. Buying an engine and slapping on a bunch of parts without knowing how to tune your engine and conduct to basic diagnosis is asking for hours of frustration.

    Take the time to properly setup your engine and have an understanding of what you are doing before adding any modifications. Teach yourself.

    This forum has a wealth of information if you are willing to search for it and ask questions of other members and use the information that is given. Sometimes a problem can be solved with a quick question and a quick answer. Other times it requires testing of different components to see if the problem is resolved. Unfortunately we live in a society where everyone wants a quick answer and is not willing to take the time to teach themselves. We want some one else to solve their problems.

    Good Luck with your new engine.

    Chris
    AKA: BigBlue
     
  15. Groove

    Groove New Member

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    I think Dimentio's on the right track. Everyone has their style when it comes to experimenting around with these funky engines.
     
  16. dimentio

    dimentio New Member

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    I got my voodoo expansion chamber hooked up with the RT carb, my bike runs better but i still have low torque at low rpms. im going to try using rubber pads on the motor mounts and using one of the bigger jets provided with my RT carb.
     
  17. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Rubber mounting is a bad idea, it just allows the engine to flop around. It's not going to help running issues.
     
  18. Greg58

    Greg58 Active Member

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    What you have is a small 2 stroke engine that does not develop a lot of torque at low rpms, a 4 stroke will have more low end torque. If you need low end you can change to a larger rear sprocket, but the top end speed will be slower. I just pedal at start or on grades.
     
  19. maniac57

    maniac57 Old, Fat, and still faster than you

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    A two-stroke will have better power at any given state of tune. Twice as many power strokes.
    Four-strokes are only playing catch up from the start.
    Motocross had to give them twice the displacement to make them competitive with the ring-dingers.
     
  20. Greg58

    Greg58 Active Member

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    I have owned 4 2 stroke dirt bikes and am aware of power for racing at high rpm, what Im saying is we are on a bicycle and sometimes you have to help these little engines out.
     

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