ASSEMBLY OF CARBURETOR THROTTLE BODY

TM 10-3930-623-34

5. Install throttle shaft hole plug (11) in side

6-50. ASSEMBLY OF CARBURETOR FUEL BOWL

opposite throttle lever. Use a light hammer to drive plug

BODY.

in flush with face of boss.

1. Install packing (35, figure 4-20) in open side of

6. Install idle adjusting needle (3) and friction

retainer (36). Place completed assembly on suitable

spring (4) in threaded passage at side of throttle body.

driver with packing facing small end of driver. Insert

Turn idle needle in lightly against seat, then back out

small end of driver into choke shaft hole; start retainer

needle 1-1/4 turns as a preliminary setting.

into counterbore of body. Lightly drive retainer into body

7. Install idle jet (44) in counter-bored passage of

until flush with machined surface.

machined surface.

2. Install shaft hole plug (34), using light hammer.

8. Install fuel valve seat (part of 16) and fiber

3. Refer to match marks made at time of

washer (17).

disassembly and install choke bracket, bracket attaching

9. Place new throttle body to bowl gasket (2) on

screws and lock washers (23 through 31).

machined surface of throttle body. Install fuel valve

4. Install choke shaft and lever assembly (32).

needle (part of 16) in seat and position float assembly

Rotate shaft so that cut out section faces out.

(18) in hinge bracket.

5. Start choke plate (20) into place (poppet valve

10. Insert float pin (19) through hinge bracket at side

stem and spring facing into air intake). Press choke

opposite slot and guide axle through float bushing.

lever against shaft boss to compress ratchet pin spring;

Press pin through slotted end of bracket, using handle of

center choke plate in closed position and start choke

screwdriver.

plate screws (21) into place. When plate is properly

11. For correct float chamber fuel level, check

centered, tighten screws securely.

distance from top of floats to machined surface of throttle

6. Install choke lever spring (22) to return choke to

body (no gasket) with throttle body inverted.

Top

wide open position.

referred to is actually lower surface of float when

7. Install main jet (42) and fiber washer (43) in

carburetor is in installed position. Distance should be

threaded hole at bottom of fuel bowl.

1-5/32 inch plus or minus 1/32 inch. To increase or

8. Install well vent jet (45) in fuel bowl and tighten,

decrease distance, use long nose pliers and bend lever

using small screwdriver.

close to float body.

9. Install discharge jet (40) and fiber washer (41) in

large threaded passage below fuel bowl.

NOTE

10. Install drain plug (37) in threaded passage at

Do not bend, twist or apply pressure

bottom of fuel bowl.

on the float bodies. The float bodies

11. Install main passage plug (38) with fiber washer

when viewed from the free end of the

(39).

float bodies must be centered and at

right angles to the machined surface

6-51.

ASSEMBLY OF CARBURETOR THROTTLE

and must move freely on the float

BODY.

axle.

1. Insert throttle shaft packing (13, figure 4-20 ) in

12. Insert venturi (46) in throttle body bore, large

open end of retainer (12). Place completed assembly on

opening first. Position with flat side toward well vent jet

suitable driver with packing facing small end of driver.

when carburetor is assembled.

2. Insert small end of driver into throttle shaft hole.

13. Carefully place fuel bowl assembly on throttle

Start retainer into counter-bore of throttle body.

body assembly, being careful not to damage floats.

Lightly drive retainer into body until flush with machined

Align screw holes in fuel bowl with holes in gasket and

surface or slightly below surface to avoid interference

throttle body.

with throttle lever.

14. Start all four bowl to body screw and lockwasher

3. Insert throttle lever and stop and shaft assembly

assemblies (1). Tighten screws uniformly and securely.

(7) in throttle body. Rotate throttle shaft to wide open

15. Replace hex plug in side of throttle body (if

position and insert throttle plate (5) into shaft. Then

removed).

rotate to closed position and hold plate closed with

16. Hold throttle lever in closed position and turn

fingers.

throttle stop screw (9) in until it just contacts the stop pin;

4. Start throttle plate screws (6) and leave screws

then turn screw in 1-1/2 additional turns as a preliminary

loose. Center throttle plate in throttle bore and tighten

idle speed adjustment.

throttle plate screws.

6-12