Carter Model N carb on Whizzer J engine

Discussion in 'Whizzer Motorized Bicycles' started by DadNamedSteve, Sep 19, 2012.

  1. DadNamedSteve

    DadNamedSteve New Member

    I picked up a Carter Model N 655 on eBay. As I was cleaning it up I wondered if I could convert this to a Model N 703 by replacing the Brass Main Nozzle and adding a new High Speed Main Fuel Needle Adjuster made for the Model N 703.

    I looked it over and it looks exactly like my Carter Model N 703, except for the fixed High Speed adjustment. I don't know if the Model N 655 was ever used on a J engine like mine or if it was only used on an H engine.

    Does anyone have any experience with this? I was wonder if it would be better to leave it as a Model N 655 or it would be more saleable if it were a Model N 703. I can only image that the 655 evolved to the 703 for a good reason but I don't know what vintage Whizzer people are looking for.

    Perhaps someone with the knowledge could post some additional information.

    Below I have provided some pictures:

    I have no idea why it needs a Welch Plug but I guess that when gas freezes that it expands.
    carter model N 655 - welch plug.jpg

    The Throttle is in good shape and I hear that a throttle shaft bushing can be added to make the seal perfect.
    carter model N 655 - throttle.jpg

    The actual Number is not easy to see, before I cleaned it up I wasn't sure what I had.
    carter model N 655 - number.jpg

    The cast aluminum housing is identical to by Model N 703
    carter model N 655 - model.jpg

    The brass bowl is in great shape, you can't see it but the bowl nut is threaded into an internal part that has all its threads (no striped threads)
    carter model N 655 - l side.jpg

    I understand that all Whizzer Carter Model N's had a fuel inlet from the top and not from the side.
    carter model N 655 - model.jpg

    You can see the Fixed high speed screw on the top
    carter model N 655 - fixed high speed.jpg

    This shows the Choke plate with spring and ball detent still intact.
    carter model N 655 - choke.jpg

    There is a small dent in the Brass bowl, but overall its in good shape.
    carter model N 655 - bowl.jpg
    Last edited by a moderator: Dec 15, 2015

  2. WZ507

    WZ507 Member

    The Welch plug is to seal the low speed circuit where the idle fuel supply passage meets the fuel-air mixing chamber near the throttle plate.

    If you are interested in getting the adjustable main jet I believe Fred White of Whizzer Fred's Classic Motorbike Parts has all parts for the subject Carter carbs., 330-537-4182.
  3. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Both versions of the Carter were used on the "J" motor, however the Carter with the adjustable main jet was used on the later "300" and "300S" motors. During the changeover from the fixed jet Carter to the adjustable jet version, Whizzer used the Tillotson ML5b carburetor on some of the "J" motors.

    As far as I know the value is the same between the 703 and 655. Carter also made the 704 and 666 vesion [had slotted mounting holes] for the Whizzer motor.

    Have fun,
  4. DadNamedSteve

    DadNamedSteve New Member

    Does anyone have a carter model n 703 they would want to trade for some u.s. currency?

    I sent mine off to a well known carburetor repair shop and they broke it so it won't work without getting a part that is no longer made.
    They are looking for one on e-bay to get the part they messed up, but this could take a long time to find one there.
    I was hopping i could just buy a different one and use the one they broke as a spare when i finally get it back.
    I hope I don't have to buy a whole J engine just to get a carter model n 703 carburetor.

    Let me know if you have any ideas where I can get one.

    Last edited by a moderator: Dec 15, 2015
  5. mason_man

    mason_man Active Member

    Fred White makes repairs and repair parts for carter carbs.
    WZ507 gave his email and number, you can save some money by sending it to him.
    was it the bowl screw?

    Last edited by a moderator: Dec 15, 2015
  6. DadNamedSteve

    DadNamedSteve New Member

    I sent it to them to see if they could get the main nozzel out. It was seized up and the brass was begining to strip. I was told that the only way was to drill it out and replace it with a new one. They drilled it out alright, but didn't realize that they couldn't get a replacement nozzel for that model until after the original one was destroyed.

    I'll call Fred. I've heard his name mentioned alot but I've never bought anything from him.

    I was thinking of selling the Carter Model N 655 shown above because I was sure this place could fix my Carter Model N 703. I'm glad I didn't. I put it on my 1949 Pacemaker Model J engine and it works fine. It's just that the Pacemaker had a 703 on it for 63 years and I hate to change it now.
  7. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor


    I have a lot of Carter parts and there is a good chance I may have the part you need. If so, I will give the part to you, you will just need to cover the shipping cost.

    Contact me via PM or email.

    have fun,
  8. DadNamedSteve

    DadNamedSteve New Member

    I ended up sending both the model 655 and the 703 to Fred White to see if he could repair them. I think he undercharged me so I left him a tip. I gotta talk to him about his rates they seem too low from my point of view. He's worth everybit and more. Did a good job and had a quick turn around.

    He converted the 665 to a 703 and even stamped the new number on the carb to match what was done back in the day.
    665 to 703 conversion.jpg

    Fred fixed the stripped brass bowl threads on the 703 by machning off the old cast aluminumn part and somehow installing a new brass fitting that worked good.
    replaced fixed hs.jpg

    Fred then installed a new High Speed main nozzle and adjusted everything.
    Now I have a good carb and a spare.
    machined surface.jpg

    I should have sent them to Fred a while back and saved me some frustration.
  9. mason_man

    mason_man Active Member

    Sounds like you'll have to start a new project now to put on that renewed carb, with Fred's low prices you'll be able to buy alot of stuff.