Service And Repair Procedure; Disassembly; Reassembly; Cleaning - Wisconsin VH4D Repair Manual

Adjust the idle adjusting needle to obtain smooth idling of
the engine at idling speed. Turn the needle out (counter-
clockwise) to make the mixture richer, and in (clockwise)
to make it leaner.
CHOKE PLATE VENTURI
(CLOSED POSITION)
THROTTLE
PLATE
PARTIALLY
CLOSED
POSITION)
INSPECTION OF PARTS
1. Float Assembly -- Replace if loaded with gasoline, da-
maged or if float axle bearing is worn excessively. In-
spect float lever for wear at point of contact with fuel
valve needle. Replace if wear is excessive.
2. Float Axle -- Replace if any wear has occurred on the
bearing surface.
3. Fuel Valve (Needle & Seat) Assembly -- Replace as
complete unit. Wear of any of these parts can seriously
affect the operation of the float.
4. Idle Adjusting Needle- Inspect tapered end of the
needle to make sure it is smooth and free of grooves.
Replace if pitted or grooved.
5. Gaskets, Seal and Retainer -- Replace all gaskets,
throttle shaft seal and retainer each time the carburetor
is overhauled.
6. Check Specifications. Verify the correctness of the
following parts. Numbers will be found on the parts.
Main Jet, Idling Jet and Fuel Valve.
Fig. 4 CHOKE SYSTEM
SERVICE AND REPAIR PROCEDURE
IDENTIFY CARUBRETOR
Check the numbe~ on the metal idgmification disc pirm~d to th~ top of
the tRrottlc body or indented in iL Tim plain nurnbc~ is the Zenith
assembly number, the numb~ with the lc[~cr "L" p~-fixcd to it is Wis-
Con Total Powcr's part numbcx for the complem assembly.
EXPLODED VIEW (Page 3)
The exploded view identifies the serviceable component
parts of the carburetor and shows their relationship to the
complete assembly. Use the key numbers on the exploded
view to identify and locate parts when performing both the
disassembly and assembly operations.
DISASSEMBLY
SEPARATE CARBURETOR BODIES
Remove the three bowl assembly screws (45,
46) and
separate fuel bowl (39) from throttle body (26).
DISASSEMBLE FUEL BOWL
1. Remove the main jet plug (43) and fibre washer (42),
using a 9/16" open end wrench.
2. Remove the main jet (41) and fibre washer (40), using
Zenith Tool No. C161-83 main jet wrench.
3. Remove the Idle Jet (38), using a small screwdriver.
4. Remove the bowl drain plug (44).
DISASSEMBLE THROTTLE BODY
I. Remove the float axle (35) by pressing against the end
with the blade of a screwdriver.
2. Remove the float (36).
3. Remove the fuel valve needle (31), using the fingers.
4. Remove the fuel bowl to throttle body gasket (37).
5. Remove the main discharge jet (32), using a small
screwdriver.
6. Remove the fuel valve seat (31) and fibre washer (30),
using Zenith Tool No. C161-85.
7. Remove the idle adjusting needle (17) and spring (18).
CLEANING
Thoroughly clean all metal parts in Bendix Metalclene or
Speedclene and rinse incleaning solvent. Blow out all pas-
sages in throttle body and fuel bowl with reduced air pres-
sure. Be sure all carbon deposits have been removed from
throttle bore and idle discharge holes. Reverse the flow of
compressed air through all passages to insure the removal
of all dirt. NEVER USE A DRILL OR WIRE TO CLEAN
OUT JETS OR IDLE HOLES.
REASSEMBLY
ASSEMBLY OF THROTTLE BODY
1. Install the fuel valve seat (31) and fibre washer (30),
using Zenith Tool No. C161-85.
2. Install the main discharge jet (32), using a small screw-
driver.
3. Install fuel valve needle in seat (31), followed by float
(36) and float axle (35). NOTE: Insert tapered end
float axle (35) into float bracket on side opposite slot
and push through the other side. Press float axle (35)
into slotted side until the axle is centered in bracket.
4.
FLOAT SETTING
a. Fuel Level, Check position
of float assembly (36),
for correct measurement to obtain proper fuel level by
using a depth gage. NOTE: Do not bend, twist, or
apply pcessure on the float body.
b. With bowl cover assembly (26)in an inverted position,
viewed from free end of float (36), the float body must
be centered and at right angles to the machined sur-
face. The float setting is measured from the machined
surface (no g~sket) of float bowl cover to top side
float body at highest point. This measurement should
be 31/32% plus or minus 1/32".
c. Bending Float Lever. To increase
or decrease dis-
tance between float body (36)and machined surface
(26) use long nosed pliers and bend lever close to
float body. NOTE: Replace with new float if position
is off more than 1/16".
5. Install throttle body to fuel bowl assembly gasket (37)
on machined surface of throttle body (26).
6. Install idle adjusting needle (17) and spring (18). Screw
needle IN (clockwise) until it seats lightly against the
idle discharge hole, then back it out 1~/2 turns as a pre-
liminary idle adjustment.
REASSEMBLE FUEL BOWL
I. Install the main jet (41) and fibre washer (40), using
Zenith Tool No. C161-83 main jet wrench.
2. Install the main jet hex plug (43) and fibre washer
(42), using a 9/16" open end wrench.
3. Install the idle jet (38), using a small screwdriver.
4. Install the bowl drain plug (44).
REASSEMBLE CARBURETOR BODIES
Install the three bowl assembly screws (45, 46) through
the fuel bowl and into the throttle body and draw down
firmly and evenly.
SPECIAL TOOLS
The special tools recommended are:
1. C161-83 Main Jet Wrench.
2. C161-85 Fuel Valve Seat Wrench.
35