Need some ideas on how to mount this engine

Discussion in 'Spare Parts, Tools & Product Developement' started by birdmannn101, Jan 31, 2013.

  1. birdmannn101

    birdmannn101 Member

    I picked up this 49cc 2 stroke off a mini chopper. It comes with it's own metal engine mount. I am just trying to figure out how to attach the mount to the bike. Here is a picture of what I am trying to do. Any suggestions will be appreciated...Dan


  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Use a 4 stroke engine mount like this.

    What kind of gearbox are you going to use with that motor?
  3. birdmannn101

    birdmannn101 Member

    Thanks for the link on the V frame mounting plate. I don't see how it would connect to the bars or any size for it's length.

    The gearbox is included in the engine. One gear with centrifugal clutch. Capable of bringing a mini chopper with smaller wheels to 40 MPH. This engine comes with pull start, centrifugal clutch and electric start. I traded another 200cc Longshen engine straight across for it.
  4. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Those mounting plates come in all the 50 cc 4 stroke kits and work on the
    cruiser style of frame which has a 1 1/2" dia front down tube.

    That 5 to 1 ratio gearbox reverses the direction of rotation for the engine so
    your CCW engine would be rotating clockwise.

  5. loquin

    loquin Active Member

    Also, if your motor has the starter/generator on it, it's going to be VERY wide, frame-mounted... Gonna leave you bow-legged!

    Because of their width, these motors are typically found in rack mounts.
  6. birdmannn101

    birdmannn101 Member

    Thanks Lou,

    Your right about the width. It is 8 1/2" wide


    and that is why I wanted to see how this mounting plate


    with no dimensions on length or a side view to show how it attaches to the bars would work with this engine mount.


    When you say rack mounts are you talking about mounting the engine on something like a rear mount?


    If so, could you recommend one that would hold up to the strain of the chain pull and engine vibrations?

  7. birdmannn101

    birdmannn101 Member

    When I pull the starter it rotates counterclockwise. Maybe I didn't catch what you meant in the quote MotorBicycleRacing.

  8. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    You must be looking at it from the other side.

    If you are looking at that gearbox from the sprocket side and rotate the
    bell CCW as the engine would turn it the gear will rotate CW.

    That 5 to 1 gearbox reverses the direction of rotation.

    PS: I have one of those gearboxes and the scooterguy used them to
    drive the bike gears on the RIGHT side of the bike.

    Last edited: Feb 5, 2013
  9. birdmannn101

    birdmannn101 Member

    Well, I guess I should be looking at a Lou's idea of a rack mounted engine. That way I could mount the engine dependent on the CW or CCW rotation? The guy I bought the engine off of kept the mini chopper so I asked him which side the chain was on and he said the left side. But heck, he is the one that took the engine apart and broke the rings while was cleaning it. Now, don't that beat all? Gave me the engine in a box.
  10. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Something like this would work for your setup.

  11. birdmannn101

    birdmannn101 Member

    How much would something like that cost? It looks like that might be my only option. The complete engine is 12 inches wide. What would you use to support that 9 inches on the left side of the bike?
  12. V 35

    V 35 Member

    As a metalworker, I'd say cut the frame, weld in a motor plate, get the plate down as low as possible, the lower the plate, the shorter the chainpath, and gyroscopic effect of motor minimized. A high mounted engine wants to ' torque ' the bike to one side during acceleration

    Most 4 stroke guys do away with pedals, if you need them for legality, check out Graucho's photo collection . In my opinion, welding
    [ brazing ] is needed to build a safe bike .
  13. birdmannn101

    birdmannn101 Member

    Never thought about "the lower the plate, the shorter the chainpath, and gyroscopic effect of motor minimized." Thanks. Looks like I'll do away with the pedals and find a good welder. You wouldn't happen to have a picture of what the motor plate should look like, would you?