2 or 4-stroke

Discussion in 'Welcome to the World of Motorized Bicycles' started by jturn, May 16, 2010.

  1. Commander Billypool

    Commander Billypool New Member

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    Well these bikes are typical I'll post one I've yet to reassemble. These are neat engines but unless you have friends with knowing on them I'd suggest electric front hub kit if you don't want to waste your time tightening nut's bolts or replacing parts .
     
  2. Commander Billypool

    Commander Billypool New Member

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  3. Slogger

    Slogger Member

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    I like the cg engines. They slip into the frame, are narrow, light weight, easy to fix and cheap.
    To me the 4 strokes look like a lump, cost more, are heavier (counting their mounting plates), need wider cranks (don't they?) and use centrifugal clutches which I grew to hate as a kid on mini bikes.
    The 4 strokes also require a little more knowledge to work on, with their valve clearance adjustments and whatnot.
    The 2 strokes need mixed fuel and some people have problems with vibration loosening mounts and stuff. Mine hasn't had any problems so far.
    Runs great and gets better every ride. I did put a different ignition and carb, but that was a choice, not something it needed.
     
  4. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    I still like my 4-Strokes a lot.....they're fast!

    [​IMG]

    :D
     
  5. dmb

    dmb New Member

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    yeah scotto, and if someone put a cr500 in a bike, you would be the first one to check out the brakes..... at speed of course. dennis
     
  6. scotto-

    scotto- Custom 4-Stroke Bike Builder

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    You got that right my friend......of course :D
     
  7. maniac57

    maniac57 Old, Fat, and still faster than you

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    " and use centrifugal clutches which I grew to hate as a kid on mini bikes."
    I could not have said it better.
    So I won't try.
     
  8. scotto-

    scotto- Custom 4-Stroke Bike Builder

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  9. Slogger

    Slogger Member

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    Very cool, Scotto it's got a lumpy idle ;)
     
  10. dmb

    dmb New Member

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    he,he,he,he, shoulda known ''the need for speed''
     
  11. SuperDave

    SuperDave New Member

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    Its cool you ask others for advice about these machines, but in the end it all boils down to personal preferences & abilities.

    Mountain bikes often incorporate a suspension for a smoother ride, but lack the visual appeal of a cruiser design. You can look cool or ride in comfort, but you can't have both, not for cheap anyways.

    2-strokes offer the best cost efficient solution to motorizing a bicycle. They are very cheap, lightweight, very simple, and offer the best acceleration to weight ratio. They also look much more like their bigger, older motorcycle cousins. They also bear the shame of lowest quality & reliability. A mechanical aptitude is manditory to setup, own & operate a HT ChinaGirl.
    Electric motivation is the easiest setup, quiet & environmentally friendly. Its also the slowest, with a limited range, sluggish acceleration, very heavy, and the highest cost of ownership: expensive to buy, expensive to replace batteries.
    4-strokes offer a cheaper alternative, with greater reliability over most 2-strokes. However, all things being equal, 4-strokes lack the torque (hill climbing grunt and accelleration) that 2-strokes have. The increased complexity of a 4-stroke also adds to the cost & weight. 4-strokes can have a higher output & top speed when compared to a same sized 2-stroke, but not always.

    So in the end it boils down to preferences & skill level. If you don't know the difference between a socket wrench and an allen wrench, take the bus. But if science & math are your thing, then by all means get a ChinaGirl, it takes a clever mind to wrap your head around the chemistry, physics & mathmatics of a 19th century designed powerplant.

    And check with the campus you attend, many schools forbid motorized vehicles on their property (except wheelchairs for the disabled). You don't want some trigger happy rent-a-cop to send you and your bike home to momma in a box.
     
  12. Scol

    Scol Member

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    I after selling my 66cc 2 stroke and buying a 4 stroke 49cc kit I also bought a 32 tooth sprocket. I'm going to fit the standard 44 tooth and see how thing go if I think the engine can hanle the smaller sprocked I'll fit.
    My commute is 32 miles round trip so I went with the 4 stroke for greater reliability.
     
  13. theisaac

    theisaac New Member

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    I was just wondering about this. I have a few questions:

    - Is there a big difference between installing a 4-stroke to a 2-stroke? It seems to me that the lack of a handle clutch makes it easier to install. However, not sure if there are other changes.

    - "Pull-start", since a 4-stroke can be pull started, can one just remove the pedals and put bars to put one's feet on?

    - Centrifugal clutch, how does this work when braking or "coasting"?

    - Cost: 4-stroke engines seem more expensive.

    - Size: Are 4-stroke engines more expensive?

    I'm aiming for a smooth ride, more into comfort.
     
  14. Tyler6357

    Tyler6357 Member

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    One thing nobody can argue is that the 4 stroke motors usually weigh more and are harder to peddle home when a problem happens but many people say they are more reliable as well.
     
  15. Krealitygroup

    Krealitygroup New Member

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    I have a four stroke.. It's more comfortable to ride to a gas station and not have to mix gas... They also are more reliable, as I've had a two stroke.. on the same exact frame
     
  16. jmason92

    jmason92 Member

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    Along with the other benefits of a 4-stroke listed on here, you can just go up to any gas station and refill, so on that end, 4-strokes are recommended. Albeit if you're running a 25-35cc 4-stroke with a Sportster tank or a bigger tank than that, you won't be refilling for a while, and that's just going to and from work, school, the grocer, the wash and dry, wherever you need to go.

    ....first 'build' will probably be a GX25 or GX35 moped conversion, or any other small 4-stroke moped conversion, to the Adventures 700c that I've been supplementing the bus with, and that moped conversion would replace public transit altogether after getting licensed on my first PTO.

    A Briggs 10hp single-cylinder or 20hp opposed-twin board tracker build is yet another idea that is to just stay in my mind for however long is necessary.

    inb4 realizing that I necroobumped. ^^;
     
    #36 jmason92, Apr 20, 2016
    Last edited: Apr 20, 2016

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