Filter
Top Products
5 . Low Idle Fuel Needle Setting: Place the throttle
into the Tdlem or %low’ position.
Turn the low idle fuel adjusting needle out
(counterclockwise) from the preliminary setting
until the engine speed decreases (rich). Note the
position of the needle.
Now turn the adjusting needle In (clockwise). The
engine speed may increase, then it will decrease
as the needle is turned in (lean). Note the
position of the needle.
Set the adjusting needle midway between the rich
and lean settings.
Adjust To
Midpo lint
Rich
Lean
6 .
Low Idle Speed Settlng: Place the throttle
control into the idle or slow position. Set the idle
speed to 1200” RPM (* 75 RPM) by turning the
idle speed adjusting screw in or out. Check the
speed using a tachometer.
NOTE: *The actual idle speed depends on
the application. Refer to the
equipment manufacturer’s
instructions for specific low idle
speed settings. The recommended
low idle speed for the Basic Engines
is 1200 RPM. To ensure best results
when setting the low idle fuel
needle, the low idle speed must not
exceed 1500 RPM.
Walbro Carburetor Adjustment
3
.Idle SDeed Screw
\
Main Fuel Needle
In general, turning the adjusting needles In
(clockwise) decreases the supply of fuel to the
carburetor. This gives a leaner fuel-to-air mixture.
Turning the adjusting needles out (counterclockwise)
increases the supply of fuel to the carburetor.
1. With the engine stopped, turn the adjusting
needle(s) In (clockwise) until it bottoms lightly.
NOTE: The tips of the fuel adjusting needles are
tapered to critical dimensions. Damage to
the needles and the seats in carburetor body
will result if the needles are forced.
2. Preliminary Settlngs: Turn the adjusting
needle(s) out (counterclockwise) from lightly
bottomed as follows or to the rich side of
adjustment.
1 WALBRO FIXED JET 1
LOW IDLE
I
I
K91
NOT APPL.
I
K161
I
NOT APPL.
I
K181
I
2-l/2 TURNS
I
1 WALBRO ADJ 1 LOW IDLE 1 MAIN FUEL 1
I
K91 1 l-3/4 TURNS 1 3/4 TURNS 1
I
K161 1 2-l/4 TURNS 1 l-1/8 TURNi 1
I
K181 1 2-I/2 TURNS 1 3/4 TURNS 1
11