Service manual

FUEL/ CARBURATOR
Float Height Adjustment
1. Illustration 1: Place the the throttle side of the
carburetor at a level position to remove weight from float
arm. In this position, the float tongue will rest slightly
outward.
2. Illustration 2: With the carburetor at rest and level,
slightly tilt the carburetor back. The float should fall into
the correct position, with the float tongue resting lightly on
the inlet needle valve pin without compressing the spring.
The bottom of the float should be parallel with the float
bowl mating surface.
NOTE: If the float is past parallel with the mating surface,
the carburetor has likely been tilted back too far and the
float tongue is compressing the needle valve pin.
3. Measure the height from the float bowl mating surface
to the top of step of the float as shown in Illustration 2.
Both sides of float should be parallel to each other.
Themeasurement should bemade at the mid-point on top
of the float using Float Adjustment Tool or a caliper.
When measuring the height, verify the inlet needle valve
spring is not compressed.
Float Height:
Parallel to Gasket Surface ± 1mm
Needle and Seat Leak Test
1. Install the float bowl.
2. Invert the carburetor and install a Mity-Vac™ to the fuel
inlet fitting.
3. Apply 5 PSI pressure to inlet fitting. The needle and seat
should hold pressure indefinitely. If not, inspect needle and
seat and seat O-ring or gasket.
Carburetor Assembly
1. Replace parts in proper order. Refer to the parts exploded
view or “Disassembly” steps for further detail
2. Install the pilot air mixture screw, spring, washer, and Oring
as an assembly (Mikuni Only). Lubricate the O-Ring with oil
or light grease before installation. Turn the screw in until it
lightly contacts the seat. Back out the specified number of
turns.
NOTE: The final air mixture screw must be adjusted
with the engine running.
Air Screw Base Setting
(Set at Factory)
Factory Specification:
1 Turns Out
6.15