Start power!

Discussion in 'Motorized Bicycle General Discussion' started by Flathead, Aug 9, 2015.

  1. Flathead

    Flathead Member

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    How do I get better low end power out of my engine? Is this a change in my carb?
     
  2. Davezilla

    Davezilla New Member

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    Welcome to the forum
    It would really help if you told us what engine you have then we could better help you.
     
  3. Flathead

    Flathead Member

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    I believe it is 66cc/ thou no markings. thanks
     
  4. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Better low end? Use a larger rear sprocket.
    You don't get a lot of low end from a 2.5 hp two stroke.
     
  5. YesImLDS

    YesImLDS Member

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    You can get a lot out of a 2 stroke. It's all about tuning for RPM range you want. You can make a torque monster with nothing over 4k rpm with the right expansion chamber. But if he wants more low end with continuing power I'd recommend higher compression. Higher compression just increases power output everywhere.

    If he wants solely more low end and keep his top end about where it's at a tuned pipe will do exactly that. Port and polish and manifold matching will just make it an all around better outputting engine, but like you said a sprocket would solve his problems, but I am currently on a 36T and have no problems with large hills... Ask 2Door, he's seen it in person.
     
  6. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Sorry, saw he was new here and gave my answer as a simple option.

    Of course, with a tuned pipe, porting, ect. you'd be getting more like 3.5 hp, lol.
     
  7. YesImLDS

    YesImLDS Member

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    I'd hope I have more than 3.5hp :p
     
  8. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Well....anything is possible.
     
  9. Flathead

    Flathead Member

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    Lots of options thanks will start with sprocket!!!!!
     
  10. 2door

    2door Moderator
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    Welcome to the forum, Flathead. I'm guessing from your screen name that you know a little about eraly Fords.

    "Low end power" tells me you're not interested in top speed. That's wise. These are after all motorized bicycles, not motorcycles and getting up from a dead stop to a decent cruising speed is important. A lower rear gear will help but will compromise your top end.

    What size, tooth count, are you currently running. Most Chinese 2 stroke kits come with a 44T sprocket. That's okay for most applications but heavier riders and hilly terrain might require a slightly lower rear gear. Bigger sprockets are available, 48T, 52T, 56T, even bigger like 72T but realize that every step up will decrease your top speed potential but your 'get away' should satisfy your need for "low end" performance.

    You didn't say how new the engine is or how many miles it has on it. A well broken in engine with 200 to 300 miles will give you better performace than a new one. Also it's never a good idea to start adding go-fast parts until after break in and then only do one addition or modification at a time. That way you'll have a baseline comparison to see what works, what doesn't and what needs adjustment.

    Tom
     

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