HS 142-F reverse engine and SBP freewheel brainstorming...

Discussion in '4-Stroke Engines' started by bakaneko, Aug 19, 2016.

  1. bakaneko

    bakaneko Active Member

    Hello. So, just doing some brainstorming on an idea for a new possibly cheaper way to do a shift kit for a 4-stroke HS 142-F without the jackshaft. I am okay if this doesn't work or if the power lost in the system is too great.

    If you reverse the HS engine so that the drive sprocket is on the pedal sprocket side then the rotation of the sprocket is reversed and doesnt work. However, if you place another sprocket on top of the drive sprocket and utilize only part of the drive sprocket you can get the chain to run in the right rotational direction (see picture A).

    Now, with my new pocket bike transmission it seem like I can get the drive sprocket and SBP free wheel to match up either with the existing mount holes or drilling new ones. This is what it looks like reverse now (see picture B and C).

    Thoughts on this? Would love if Pablo can comment. Just doing some brainstorming.

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    • C.JPG
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  2. Pablo

    Pablo Motored Bikes Sponsor

    Not sure you would get enough gear - chain engagement to drive the rotation.
  3. bakaneko

    bakaneko Active Member

    thx for the input. if i were to try this out, can you let me know what individual items that i might need from you? (freewheel, sprockets, axle?)
  4. Pablo

    Pablo Motored Bikes Sponsor

    Axle? Insufficient information at this time to provide a parts list.

    You should probably engineer it out a bit more and contact Jim for suggestions. Thanks.
  5. KCvale

    KCvale Motorized Bicycle Vendor

    Ya, Jim is a frigg'n genius engineer, he helped me with my design.

    The problem with doing it your way is getting enough gear reduction to the BB sprocket, and lining up the output sprocket with it.

    I have been trying everything (like you) I could think of and you know what I came up, the 10G long shaft transfer case...



    This is the best I could up with and it works like a charm, but if you come up with something even better I'm all ears!
  6. bakaneko

    bakaneko Active Member

    oke, thx for input guys. it is just a brainstorm at the moment, i will flesh it out a bit more and work with jim. cheerz
  7. Steven Main

    Steven Main Guest

  8. CrazyDan

    CrazyDan Active Member

  9. Frankenstein

    Frankenstein Well-Known Member

  10. FurryOnTheInside

    FurryOnTheInside Well-Known Member

    Not enough engagement, I think. As Pablo said to a similar idea earlier in the thread.

    I'm wondering why (or if!) a four stroke engine can't be made to run in reverse anyway? I mean apart from things loosening.
  11. Frankenstein

    Frankenstein Well-Known Member

  12. gary55

    gary55 Active Member

    Build something similar to the belt drive. Directly engage gears instead of belts and pulleys to rev. rotation. Come off the big gear with a sprocket, and chain down to the free wheel bottom bracket sprockets. A slightly more involved trans. but no j shaft. Should save costs in the long run. With a good cent. clutch it would go well. With a manual clutch it would be awesome. Their is a crude concept of what you have to build to slap onto the side of a right drive 4 stroker sitting under the clutch cover of the china girl.
    Last edited: Mar 28, 2017 at 12:05 AM
    FurryOnTheInside likes this.