2 stroke to 4 stroke conversion phase questions

Discussion in 'Motorized Bicycle General Discussion' started by Crysisfreak7, Aug 6, 2014.

  1. Crysisfreak7

    Crysisfreak7 New Member

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    If i have the entire kit that came with my 2 stroke engine, and wanted to get a 4 stroke, could i just get the engine and use all the parts i still have, sprocket, throttle, clutch, everything, on the new engine. and if so, would i go any slower or faster with the sprocket that came with the 2 stroke, i dont know if it is 44t or 48t that comes with the 2 stroke.
     
  2. ajoh

    ajoh Member

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    you can but you'll need not only the engine but the gearbox as well an the engine mounting plate
    ie, 4G drive or whatever you decide to run

    you may need 1 or 2 other things to maybe like exhaust
     
  3. The_Aleman

    The_Aleman New Member

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    A chinagirl has a 4.1:1 internal reduction and most 2-stroke kits come with a 44T sprocket, those end up being 18.04:1 overall.

    You'd have to figure out what 4-stroke kit you'd be getting to find out what new ratio you'll have, and to find out if your 44T will work for you.

    Kits with Q-Matic average about 2.76:1 at output
    Kits with pocketbike gearbox average about 3.25:1
    4G is available in 4:1 and 5:1 output

    A small 4-stroke will need a numerically higher gear ratio (>15:1) for best performance. A 79cc or higher 4-stroke can get away with a numerically lower ratio due to torque.
     
  4. crassius

    crassius Well-Known Member

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    so many things are just a tad different that I'd get a full kit for the 4-stroke and sell the 2-stroke stuff (might save you days of mods & metal bending)
     
  5. Trey

    Trey $50 Cruiser

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    Crysisfreak7- I'm checking in on your old thread, to see what you did. Did you swap mototrs? Change gears? Did you encounter anything interesting?
    Thanks! Trey
     
  6. mapbike

    mapbike Active Member

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    what poll?

    and how would any of us know you since this is your first post?
     
  7. Trey

    Trey $50 Cruiser

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