1. Home
  2. Knowledge Base
  3. Carter
  4. Carter N
  5. Carter N Whizzer Model J Carburetor

Carter N Whizzer Model J Carburetor

Whizzer Motorcycle
Carter N
1948 Whizzer Motor Bike

Carburetor numbers: N-655S, N-666S & N-704S

Flange size 1/2″, Main venturi: 7/16″

Float level: – Distance from top of float, at the free end, opposite the needle & seat to lower edge of float chamber. 1/4″

Idle Adjustment – 1 – 3 turns open. Idle rpm should not be below 1,000 RPM.

Main Jet – Calibrated to flow 65-67 CPM

Disassemble
Remove the carburetor from the engine.Remove bowl nut, gasket and bowl.Remove float pin, float, needle and seat. Check float for dents, leaks and wear on float lip.Remove bowl ring gasket.Remove main metering jet.Remove low speed jet, idle adjusting screw and idle adjusting screw spring.Remove strainer nut assembly and strainer.Remove nozzle.Remove throttle valve screws, valve, and shaft and lever assembly. Tip: Screws are sometimes mushroomed over to prevent them from falling out. Using a dremmel tool grind the ends of the screws flush with the shaft. Use the best screw driver that will fit the screw as tight as possible. Do no apply too much pressure, or the screw will break. If the screw doesn’t come loose easily, put something behind the screw, then bang on the top of the screw driver in order to jar the screw loose.Do no remove choke valve and shaft unless replacement of these parts are necessary. A spring loaded ball retains choke in wide open position. Be sure to use a new ball and spring when replacing choke shaft and lever assembly.Clean all parts, using a water based cleaner. Wash off all chemical, blow out all passages with compressed air. Using small wire, run the wire in the passages to clean out ethanol residue left behind. Be gentle, you do not want to enlarge any of the passage ways.Carter N




Assembly
Install throttle shaft and valve. Valve must be installed with trademark “c” on side toward idle port when viewing from flange side. Always use new screws. With valve screws loose and throttle lever set screw backed out, seat valve by tapping lightly with a small screw driver. Hold in place while tightening screws. The idea here is to have the valve seal as tightly as possible. Too much gap can cause a high idle situation. Same as increasing the throttle.Install nozzle, making sure it seats in casting.Install main metering jet assembly.Install needle seat, needle, float and float pin.Set float level. With carburetor casting inverted, float resting lightly against needle in its seat, there should be 1/4″ clearance between machine surface of casting and free end of float (side opposite needle seat). Adjust by bending lip of float with small screw driver.Install bowl ring gasket, bowl, nut gasket and bowl nut. Tighten securely after making sure bowl is centered in gasket.Install low speed jet, seating it securely in casting.Install open end of strainer in strainer nut assembly and install strainer nut assembly.Install idle adjusting screw, finger tight. Back out 1 to 3 turns. Do not force, or bend screw.
1A-73
Flange Gasket
21-105S
Float and lever assembly
2-127
Throttle valve
23-37
Bowl
3-611S
Throttle shaft and lever assembly
23A-19
Bowl ring gasket
7-152
Choke valve
24-23
Float lever pin
11-189S
Low speed jet assembly
25-160S
Needle and seat assembly
12-317
Nozzle – can also use 12-328
30-58
Strainer
12-328
Nozzle
30A-46
Idle adjustment screw
14-368S
Choke
39-10
Choke and throttle valve attaching screw (sup by 101-320)
15-48S
Strainer nut assembly
61-368
Adjustment screw spring
15-49
Bowl nut (sup by 15-50S)
61-369
Choke shaft spring
15-50S
Bowl nut assembly
101-31
Throttle adjustment screw
20-22
Needle seat gasket
101-320
Choke and throttle valve attaching screw
20-26
Main metering jet gasket
116-16
Choke shaft ball
20-35
Strainer nut gasket
159-121S
Main metering jet assembly
20-110
Bowl nut gasket
 
 
Updated on 12/07/2020

Was this article helpful?