Never Drilled Clutch Pivot Hole

Discussion in 'Whizzer Motorized Bicycles' started by Mikkojay, May 29, 2012.

  1. Mikkojay

    Mikkojay New Member

    I have a NE5 engine that was mounted in an Ambassador 2, and the flange in the case where the clutch arm pivot bushing normally goes has never been drilled out.
    Here is a picture:
    <img src=""></img>
    I have a 2001 Pacemaker auto clutch that I would like to try out, so I am guessing the most obvious start is to drill out the engine case and find an appropriate bushing to install. The hole in the case is just under 5/8" in diameter.
    My first concern is to not remove too much material from the case when drilling it out, as it seems like there is not a lot to spare.
    My second concern is that I fear making to hole/bushing combination too custom, i.e. if I wind up with an unconventional diameter, and I want to revert back to a standard slip-type clutch, I would be in a mess.
    I was planning on fabricating my own arm, but now that I am getting to the precision measuring stage, I feel at a loss somewhat.
    I have spent the last two days visiting no less than 6 hardware stores trying to find a bronze bushing that will work, and am still empty handed.

    I was also considering buying a slipper clutch pulley and arm combo, then trying to find a matching bushing. Then I would drill the case to accommodate the outside diameter of the bushing.

    If anyone has ever gone through a similar scenario and could offer any suggestions I would certainly appreciate it.
    Thanks, Mike

  2. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Mike,

    The original WC-1 and NE motors used 2 bushings at the rear of the motor. In typical fashion they were not a good fit, unlike the vintage Whizzer motors.

    The vintage motors used a single oilLite bushing and the O.D was 9/16" and the I.D. was 1/2". It would suggest you find a 5/8" O.D. bushing and make a pin to fit the I.D. of the bushing.

    The vintage motors had a 100% working manual clutch, whereas the new edition motors employed a very "SLOPPY" fit and allowed the clutch to sit at a very poor angle. I upgraded all my personal collection to the original design of the vintage clutch system.

    The NE arm uses a 12 MM bolt to attach to the motor and any engineer understands a bolt instead of a fitted pin allows exessive play in the clutch system.

    I would suggest you install the 5/8" O.D. bushing and make a pin to fit the I.D. of the sleeve.

    The arm on the new edition motors is too long, or too short depending on the belt option length. The stock belt on the vintage Whizzer is an AX26 [28" long] and works 100%, whereas the new edition motors uses a FHP belt [4L290] that is 29" long. The arm is simply between belt sizes. The 28" is too short and the 29" is too long. I would make the arm slightly longer and use an AX27 [29" long].

    If you need detailed pictures just let me know.

    Have fun,
  3. Mikkojay

    Mikkojay New Member

    Thanks for the detailed reply Quenton-
    I did end up going with a 5/8 OD 1/2 ID oilite bushing found on ebay. I believe it was 1 1/4 in length, so I trimmed it to fit using a cutoff wheel. I was amazed at the actual impregnated oil residue left behind when I cut the bushing. These things have more oil in them than I imagined! I used a 1/2" bolt and locking nut along with a bronze washer on my DIY clutch arm. It ended up being nice and solid. I'll add some pictures of it over on the Wasp thread when I get a bit further.
    Thanks, Mike