Some custom motor mounts for my first MB build

Discussion in 'Photos & Bicycle Builds' started by datz510, May 15, 2008.

  1. datz510

    datz510 Member

    Here's where I'm at on the 2nd evening of my build. My Fuji mountain bike has a thin aluminum frame, so I had to fabricate some custom mounts.

    Right now, I have it set up with rubber motor mounts isolating the engine from the frame. I might need to go back to a solid mount to drop the motor a bit, as the spark plug is IMO too close to the top tube of the bike.

    Here are some photos:

    This build brought to you by Killian's Irish Red.... mmmm

    CLoseups of front and rear mounts. I'm going to have to heat and bend the exhaust a little bit to clear the frame.

    A closeup of both mounts:

    One extreme to the other.. 1962 Mercedes Unimog, 11mpg. Fuji Motor Assisted Bike, 150mpg.

    A good view of the mounts. The rear is actually twisted to the side to clear the chain:
    Last edited by a moderator: May 15, 2008

  2. djase10

    djase10 Guest

    Good one mate, a novel way to mount the motor.
  3. datz510

    datz510 Member

    Oops, sorry about the IMG tags..
  4. Love the Unimog!
  5. datz510

    datz510 Member

    Almost done with it. here is the bike after tonight's work:

    Painted the engine low gloss black. Super stealthy!

    Got the controls installed. Adapted the throttle to allow use of my end grips.

    Dual pull brake lever on the right hand activates front and rear brakes simultaneously.

    And clutch on the right hand. There is a lock on the clutch so you can lock it engaged to allow normal pedaling of the bike.

    Engine is all low-gloss black. Its almost invisible. I left the carb uncoated to allow ease of maintenance.

    Here is the chain cut to length and installed. Also installed the tensioner. I'll probably come up with my own ball bearing tensioner design. This one doesn't look like its going to last very long. I may end up turning an automotive idler pulley down on a lathe to allow the chain to run on it and mount that on my own tensioner bracket.

    The motor mount turned out perfect. There's over 1/4" clearance between the chain and the rear engine mount.
  6. datz510

    datz510 Member

    Finished it tonight. Got it running and everything adjusted. Its a nice running engine! I'm really happy with it.
  7. fastboy9

    fastboy9 Member

    Brilliant! You've done a great job with that bike, looks a very clean build, the original mounts are the let down on my bike but you've have overcome that before you even reached that problem. The only thing I would recomend is that you buy a fuel filter as the fuel tanks are notorious for little bits of rust making their way into the carb (not good). You can buy them on ebay for about $3 just search for pocketbike fuel filter. Its well worth it.
    Nice job!

  8. datz510

    datz510 Member

    thanks for the advice! I'll definitely pick up a fuel filter and get it on the bike.
  9. datz510

    datz510 Member

    Here are a few more photos of the finished bike:

    The bike with exhaust and a few other new doohickeys:

    New Schwinn speedometer and odometer:

    Took it out on a 6 mile ride tonight. It performed flawlessly! I have around 10-15 miles on it so far in addition to this before I had a working odometer.

    Closeup of the slightly adjusted exhaust. I heated the downpipe with a MAPP gas torch to red hot and then bent as needed. Then painted with some low gloss black 500 degree engine block paint. Seems to be holding well.

    The back of the bike.. with crappy chain tensioner. I'm gonna have to do some reworking of it. Really cheesy design to start with.

    The carb will get a little fabrication work as well to adapt a small K&N style filter to it.

    Lotta stuff on the handlebars:

    I still need to clean up the electrical wiring a bit. Need to wire in a kill switch.

    The socket head cap screws look really nice on the engine. All the cheap chinese hardware was replaced with grade 8.8 stuff.

    And here is a trick I figured out while trying to mount the tank on my bike. My bike has exposed cables on top of the top tube, so I cut a small peice of 1/8"x 3/4" strip steel, drilled it for the tank mounting studs, and then slipped it under the cables. This lets the cables run through the cutout in the tank without binding up. The tank is then tightened down normally once the strip steel is in place.
  10. KiDD

    KiDD Member

    I would suggest going for the Champion CJ7Y because they are a lower profile spark plugs makes clearance a non-issue
  11. datz510

    datz510 Member

    Thanks for the input! I'll pick up a Champion plug tonight and see how it works.
  12. KiDD

    KiDD Member

    If you look at the pics in my sig you will see how short the plug is and how it barely clears.