My 2008 Modified Ambassador

Discussion in 'Whizzer Motorized Bicycles' started by ranger-ron, Apr 20, 2012.

  1. ranger-ron

    ranger-ron New Member

    Here are a couple of pictures of the modifications I did to my 2008 Ambassador so it more closely replicates the original 1951 model.

    The phony rear suspension and Ape hanger handle bars were the first to go.

    I also replaced the Variator with a machined 2.75" V-belt pulley and mounted it against the flywheel with the starter TB pulley on the outboard side unlike the original set up. There is no more wobble and much less stress on the crank. I added an adjustable belt idler so I could vary the ratio between the engine and variable pulley/clutch assembly. The idler will be controlled by a foot pedal which I have yet to install.

    Because the rear wheel is now in a fixed position (the wheel slots are now vertical), I needed to add a belt idler so I could tighten the main drive belt and also have more wrap around the small driver pulley. An important benefit is, the brake rotor does not move in relation the caliper when the belt is tighten. Before, when I needed to tighten the belt, the rotor would scrap against the inside the caliper. Not good! I'm also thinking about activating the rear brake via a right foot pedal rather the left-hand brake lever.

    The usual improvements were also made to the engine; Re-timed the camshaft, decked, painted and baked the cylinder and milled the head. I still need to machine the top of the head for better cooling.

    I'm still looking for a rear rack like the 1951 model had.

    Attached Files:

    Last edited by a moderator: Dec 18, 2015

  2. ranger-ron

    ranger-ron New Member

    Better Pictures

    I think these are better pictures of my Ambassador project.

    Attached Files:

  3. wheelbender6

    wheelbender6 Well-Known Member

    Lookin good.
  4. mainstreet

    mainstreet New Member

    Fantastic! I wish I had a Whizzer like that! It looks a lot better with the changes you made. My 2008 NE5 is cool, but yours is cooler! I wish I could put an electric starter on mine like your Ambassador has. Good job!
  5. RdKryton

    RdKryton Active Member

    Very nice! Just curious, do you have any over heating problems?

  6. professor

    professor Active Member

    Really nice, looks like a mini motorcycle.
  7. ranger-ron

    ranger-ron New Member

    Thanks for all the compliments everyone. I still have more modifications before I"m done.
    Jim; I only ride around my neighborhood which is about a 2 or 3 mile trip, so it doesn't get much of a chance to overheat.
  8. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi ranger-ron,

    Another inportant modification to consider is the tires! After replacing the tires several times on my 2007 Ambassador, and every tire on all NE-r, and Ambassador II brought in for service, it became clear the original tires may be dangerous. All of the original tires developed "cracked" sidewalls. After approx 500 miles the tires are basically "shot". The sidewalls on the original tires are SOFT, and easily flex and "crack".

    Many are starting to use the "baloon" 26" tires and found it adds to the ride stability, and provides a much quicker take-off speed. The speedometer is also correct when using the 26" X 2.125" tire. The only downside is the fenders need to be re-located to look good over the smaller tires size.

    Have fun,
  9. Mikkojay

    Mikkojay New Member

    Hi Ranger-Ron, nice job on the modifications- looks like a definite improvement. I am in the midst of trying to figure out a similar alternative. I have an '08 Ambassador, and there is no way I am keeping the stock clutch setup as-is. I am going to pull the motor and put it on another bike, so I have a "blank slate" if you will.
    Could you provide some more details and photos (if you have) of the machined 2.75” V-belt pulley you mention in your first post? Did you have access to a lathe and fabricate something yourself?
    Thanks, Mike
  10. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Everyone,

    It is important to note the 2007 Ambassador uses the same automatic clutch as all 2005 and up models.

    My 2007 Ambassador [very rare] has the automatic clutch and starter drive. The CVT drive just didn't work out well and is very problematic on the later models.

    Look at the motor and notice the bushing at the upper rear of the motor. This was the location for the clutch arm and automatic clutch on all models from 1999 to 2007.

    Everyone should be aware, the rear of the CVT drive is the most problematic, not the front part of the drive. It is also important to note the shaft that the rear clutch is connected to can, and does "snap" at the location where it enters the frame. The rear clutch also has a serious spring problem as many where shipped with the wrong spring [you can tell by the color of the spring].

    Any effort to reduce the length of the drive system attached to the crankshaft is a "good" thing, and will increase engine life [crankshaft bearings].

    Both the NE-r, and the Ambassador II can be converted to the earlier clutch system and can be started by moving the bike forward. I used this method for the last several years on my 2007 Ambassador because of a constant "dead" battery. The major difference between the NE-r and Ambassador II CVT drive is the one-way bearing used on the NE-r to be able to pedal start the motor. If the battery is dead on the Ambassador II you must install a special pin in the CVT to lock the drive to "push" start the bike.

    Have fun,
  11. ranger-ron

    ranger-ron New Member

    Mikkojay, Here is a picture of the first pulley I tried. At 3 3/8" dia, it was too big so I dropped down to a 2 3/4" pulley. Notice the 6 reliefs milled into the flywheel side of the pulley. They are for clearance for the rivets that attach the flywheel hub to the flywheel (see picture) They allow the pulley to fit snugly against the hub which helps the pulley to run true plus they keep the pulley from slipping on the hub. I couldn't believe the original set up didn't have the milled reliefs in the back of the starter drive causing it rest against the head of the rivets, not the hub. No wonder the whole set up wobbled. I made a .625" OD X 12MM ID bushing so the pulley fit properly on the 12mm X.25 X 90 MM long crankshaft bolt. There is also a new bushing behind the large starter timing belt pulley.
    The other side of the pulley just has a flat machined surface which mates up to the flat back side of the started drive.
    The jack-shaft that the clutch is on, was shorten to about 8 3/8" so the clutch lines up to the new crankshaft pulley (see picture). Hopefully by moving the clutch inward and having the 2 belts pulling against each other will help keep the shaft from snapping off. I also try not to over tighten the main drive belt.
    The front belt is a L425 and, because of the new idler, the longer belt is now a AP71.
    It's all working far!

    Attached Files:

  12. Mikkojay

    Mikkojay New Member

    Great job ranger-ron, oh to have a Bridgeport in my garage (with an indexer) :)
    Yes, Quenton was telling me about the need for those reliefs. It all makes sense. (or no sense if you're talking about the original designers!) anyway, it looks like you are making the best of what you have there.
    Thanks so much for the details!