Fuel System Operation and Tests
CHANGE ENGINE RATED SPEED AND
ADJUST DROOP--IN-LINE INJECTION
1. Start engine and apply 50% load at rated speed until it
reaches operating temperature. Remove cap nuts from
adjusting screws before making adjustments.
2. When the engine has reached normal operating
temperature, adjust fast idle (stop) screw (A) clockwise
(CW) to 1500 rpm (50 Hz) with 100% (full) load.
3. Remove load and back out the idle (bumper) spring
screw (E), while observing the corresponding drop in
engine rpm's until engine quits losing speed.
4. Screw in idle (bumper) spring screw until engine speed
increases 5--10 rpm.
5. Check for specified no-load (frequency). If governor
regulation is within 5--7% range, proceed to Step 8.
NOTE: A noticeable click will occur at each 1/4 turn of
droop adjusting screw. One click CW will increase
no-load speed approximately 10 rpm,
A--Fast Idle (Stop) Screw
counter-clockwise (CCW) will reduce speed by 10
B--Droop Adjusting Screw Access Plug Location
C--Droop Adjusting Screw
D--Slow Idle (Adjusting) Screw
6. If governor regulation is above 7% or below 5%, stop
E--Idle (Bumper) Spring Screw
engine and remove droop adjusting screw access plug
G--Mechanical Shutoff Lever
(B, shown removed) from top of governor housing.
a. Back out slow idle (adjusting) screw (D) and
bumper screw. Pull back on throttle lever (F, toward
rear of governor housing) by hand until the droop
adjusting screw (C) inside housing can be adjusted
through the access plug hole.
b. Screw the droop screw in (CW) counting the turns
until screw bottoms out. Then, return screw to
c. Screw in the droop screw (CW) no more than 1/2
turn (two clicks) at a time to reduce governor droop.
CCW no more than two clicks at a time to increase
governor droop (to reduce governor sensitivity).
Continued on next page