Waterax MARK-3 Owner's Manual page 19

Before reassembling the carburetor (in reverse order as outlined previously), wash all component parts in
carburetor cleaner and blow off with compressed air. The channels in the metering body should be
cleaned by blowing through the low and high speed adjusting orifices. All fuel passages in the three
castings should be cleaned with compressed air.
Do not clean orifices or passages with wires or drills as this might damage and cause incorrect operation
of the carburetor.
When reinstalling O-ring type adjusting screws, lubricate with SAE-30 oil to prevent seizing. Packing
spring type adjustments do not require lubrication.
When reassembling the inlet control lever and spring, make sure that the spring rests in the well of the
metering body and locates on the dimple of the inlet control lever.
Do not stretch spring. Inlet control lever is properly set when flush with floor of diaphragm chamber.
Be certain main diaphragm, gasket and cover casting are carefully fitted over the three small pins cast in
rim at bottom of metering body. The fuel pump gasket, diaphragm and fuel pump body are placed over
similar pins at bottom rim of main diaphragm cover casting. Evenly tighten fuel pump body retaining
screws to insure complete seal of casting separations of both diaphragms.
Frequent cleaning or replacement of the fuel strainer screen will aid satisfactory operation of the
carburetor.
To test the carburetor:
•
Pop-off pressure: 8-12 psi
•
Reseating pressure: 4-5 psi
Carburetor adjustments
There are three adjustments on the carburetor (see image):
A. Low speed (idle) mixture adjustment screw ("L")
The low speed mixture screw controls the air-to-fuel
mixture ratio at idle and low speeds.
B. High speed (main) mixture adjustment screw ("H")
The high speed mixture jet screw controls the air-to-fuel
mixture ratio at high speeds.
C. Idle speed adjustment screw
The idle speed regulating screw controls the idle speed.
Turning the mixture screws clockwise (CW) will close the jets and lean out the mixture (more air, less
fuel). Turning the screws counter-clockwise (CCW) will open up the jets and richen up the mixture (less
air, more fuel).
1. Before starting the pump unit, close both high and low speed adjustment screws by turning CW until
they just touch the seat.
Turn adjustment screws carefully and gently. Do not force needle into seat; otherwise,
Note:
both needle and seat may be permanently damaged.
2. The entry settings are as follows:
•
High speed: open jet by turning one (1) turn CCW from fully closed.
•
Low speed: open jet by turning one (1) turn CCW from fully closed.
3. Turn idle speed regulating screw until throttle shutter is slightly open.
4. Install a 1/4" [6.35 mm] nozzle tip at the discharge hose.
03/2016 – Page 19 of 52
WATERAX MARK-3 Owner's Manual