6-03
Governors
6-03
FIG. 3 Altitude Compensation Adjustment
VELOCITY GOVERNOR
RPM ADJUSTMENT
until the tangs on the tool engage the slots in the adjusting
Adjustment of the velocity governor is made with a
bushing. If the tool will not engage in the adjusting bushing
tachometer attached and the engine at normal operating
slots, note the position of the tool and rotate the tool slightly in
temperature.
either direction until engagement is achieved. If it is necessary
Operate the engine at wide open throttle and check the
to rotate the tool more than 1/6 turn (I flat of the hex head) to
rpm.
accomplish engagement. rotate the tool back to its insertion
If adjustment is required or desired. remove the governor
position and pull the tool out. Rotate the tool 1/6 turn in the
seal.
direction required to achieve engagement and re-insert it
To increase the rpm, turn the cap counterclockwise.
ADJUSTMENT TABLE
When the adjustment is complete. stop the engine, seal
The altitude adjustment table specifies the amount from
the cap and remove the tachometer.
the factory setting that the tool should be rotated to adjust the
ALTITUDE COMPENSATOR
velocity governor for altitude operation. For an increase in the
The characteristic of velocity-type governor is that the
average altitude of operation, rotate the tool the specified
regulated engine speed increases in direct proportion to any
amount in the counterclockwise direction.
increase in the altitude is which the engine is operated. This
Remove the tool and install the adjusting cap. Do not turn
also causes a proportionate increase in the spread between
the adjusting cap. Install the tachometer and check and adjust
full load and no load setting. A normal seal level no load
the no load setting of the governor with the adjusting cap. It
setting of 3000 engine rpm becomes 3300 engine rpm at 5000
the altitude adjustment was done properly. the no load and full
feet above sea level. The 300 engine rpm spread at sea level
load spread will be within specifications. Seal the adjusting cap
becomes a 500 engine rpm spread at 5000 feet above sea
to the governor body.
level.
Trouble shooting is using the proper adjusting procedure.
The altitude compensating governor can be adjusted to
If the governor cannot be adjusted it will have to be replaced.
compensate for variations due to altitude. With the exception
However. be sure the proper governor has been installed
to the altitude compensating adjustment (Figure 3). the
for the engine application and rpm it is to operate at.
description and operation of this governor is the same on the
conventional velocity governor.
Varying Altitude Adjustment
On units equipped with an Altitude Compensating
governor, the Varying Altitude Adjustment is made on engines
that are operating at or near sea level and altitudes above
2000 feet. First make the no load adjustment as previously
explained. Then, using the adjusting cap only, adjust the no
load speed for the anticipated altitude by turning the
adjustment cap 1/4 turn in the clockwise direction for each
1000 foot difference between the altitude. The adjustment is
made and the maximum anticipated operating altitude.
Constant Altitude Adjustment
The Constant Altitude Adjustment is made on engines that
are going to be operated at a constant altitude above 2000
feet. Cut the governor seal wire and remove the adjusting cap.
Do not rotate the adjusting cap during removal.
Use a mirror and a light to observe the position of the
FIG. 4 Altitude Adjustment Table
slots in the adjusting bushing. Hold the tool in the proper
position to engage the adjusting bushing slots and carefully
insert the hex-shaped center post of the tool in the hex-head of
the adjusting of the adjusting screw. Push the tool inward