Before changing the mixture adjustments, be sure the
tank is full of clean, fresh, properly mixed fuel. Then
clean the air filter. and leave the filter and cover off
until the carburetor has been adjusted.
1. The Idle Mixture Adjustment Needle is marked "LO"
on the side of the carburetor chamber (fig 19) and
the Main Mixture Adjustment Needle is marked "HI."
VERY GENTLY (so as not to jam needles into their
orifices) turn each needle clockwise until it Just
closes against its seat. Now, open both needles one
lull turn from the gently closed position. and adjust
carefully as follows.
2. Push the throttle button all the way in. Start engine
and pump water at open discharge. When engine is
fully warmed up.
adjust the Main Mixture
Adjustment Needle (fig 19) for the highest pumping
speed obtainable. NOW, OPEN THE NEEDLE 1/8
TURN MORE. This slightly rich setting will keep
the engine from faltering during the pump's priming
3. Maximum no-load speed is limited to approximately
6500 RPM by the built-in automatic governor. The
screws holding the Governed Speed Adjust
Clamp(fig 19)should never be loosened, unless a
THROTTLE ROD ADJUSTMENT AND AIR CLEANER
reliable reed tachometer is available for readjusting
governed speed to approximately 6500 RPM.
4. Pull the throttle button all the way out, and adjust the
Idle Mixture (LO) Needle for the highest and
smoothest speed obtainable.
If the speed so
The felt wick in the fuel tank absorbs fuel which it
obtained is either too high or too low to suit
supplies on demand. The wick also acts as a filter to
operator, adjust speed by means of the Idle Speed
keep moisture and dirt out of the carburetor. This filter
Screw. (fig 19 )Usually 2500 or higher RPM is
is so large in capacity that it should never become
clogged as long as only fresh, clean fuel is used. To
5. Because the Main and Idle Needle settings are
check the fuel filter. loosen the fuel cap and disconnect
interdependent, some readjustment of needles may
the fuel line at the fuel tank outlet connection. If, with
be necessary-recheck adjustments under full load
the tank full, fuel flows by gravity from the outlet hole,
conditions, as above--be sure settings are correct
the filter is not clogged. A plugged filter will prevent the
before you reinstall the air filter and cover. NOTE:
engine from running properly.
If performance changes when you reinstall the air
VENTED FUEL CAP
filter, the filter may not be clean enough....Clean or
replace as necessary. Do not operate pump without
To determine whether the fuel cap vent (fig 18) is
operating correctly, start engine and remove the cap - if
engine operation improves, fuel cap vent may be faulty.
VENTED FUEL CAP