Table of Contents
Advertisement
FUEL SYSTEM
Float Height Adjustment
1.
Place the carburetor at a level position to remove weight
from float arm. In this position, the float tongue will rest
slightly outward.
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.
IMPORTANT: When measuring the height, verify the
inlet needle valve spring is not compressed.
Bowl Mating Surface
Parallel with Float
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.
If adjustment is required, carefully bent the float tongue up
or down to achieve the proper float height.
Float Height:
Parallel to Gasket Surface ± 1mm
4.14
Float tongue is
resting on the
spring seat
Float
Tongue
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 O-
ring 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 pilot (idle) mixture must be adjusted
with the engine running. Refer to Chapter 2 for
procedure.
Air Screw Base Setting
(Set at Factory)
Factory Specification:
50cc Mikuni: 2.5 Turns Out
90cc Keihin: 2.25 ± .5 Turns Out
Needle and Seat Leak Test
1.
Install the float bowl.
2.
Invert
the
carburetor
(PN 2870975) 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.
Image for
Reference Only
and
install
a
Mity-Vac™
Advertisement
Chapters
Table of Contents
Troubleshooting
