4 stroke gear box

Discussion in '4-Stroke Engines' started by Bikeuser, Aug 17, 2008.

  1. Bikeuser

    Bikeuser Member

    I need a new clutch for my 4 stroke engine gearbox.

    who sells the grubee gearbox and where can i find a the internal clutch part the expands when the rpm's go up

  2. stude13

    stude13 Active Member

  3. ocscully

    ocscully Member

    BirdDog/bicycle-engines.com should have the grubee replacment parts you are looking for or will have them pretty soon if they are out. You also could check with Staton-Inc They sell clutches that work with the Honda/Clone motors as well but you will need to be able to use your old clutch bell with attached driver. You need to be sure that who ever you get the replacment from that its optomized for the Honda/Clone motors specs. These motors idle at higher rpms so the basic clutch for industrial motors won't work properly without modification to the springs.

  4. jimraysr

    jimraysr Member

    GruBee Centrifical clutch

    I just got one from Bicycle-Engine a couple of weeks ago for $20 + $9 usps flat rate shipping. Had it in three days.

  5. Bikeuser

    Bikeuser Member

    Thanks alot.

    i have one of the crappy gearboxes on my engine. I know about the broken gears and whatnot. I do not want to spend 100 dollars on another gearbox. my solution is to pull the gears, clean them up, heat them orange hot in a flame quench them, and then temper them to a blue. the reason the gears fail is becuase of the poor quality of steel they use and not enough treatment. I hope this works.
  6. cgbjake

    cgbjake Member

    How has the heat treatment worked?
  7. bubbatgs

    bubbatgs Member

    I order my parts from bicycle-engines.com
  8. Gearbox blues

    Hello Bikeuser, if you pm me, I can tell you of someone who may be able to help you.

  9. Irish John

    Irish John Guest

    Why can't you get it from whoever supplied your kit Bikeuser? The clutch needs replacing about every 10,000 kms which is pretty good wear I reckon. The freewheel sprockets need replacing more often than that.
    I get mine from my Grubee supplier in Sydney, Australia. MBB Imports for $25 for clutch and $10 for freewheel sprocket.
    Any supplier who doesn't stock spares needs to be publicised on these pages so people know to avoid them.
    Drilling holes in the clutch improves it's operational performance and its lifespan as per Cheetoh's idea -0 see attached picture.
    Turning the clutch around also evens the wear on the pads.

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