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H. GOVERNORS
GENERAL
Engines currently fitted to lawnmowers, pumps etc, are
generally fitted with a speed governor which controls the
engine revolutions at a predetermined speed under
varying load conditions.
TWO STROKE ENGINES
Two stroke engines are usually fitted with pneumatic
governors.
FOUR STROKE ENGINES
Four stroke engines, horizontal and vertical crankshaft,
are fitted with mechanical governors.
NOTE - When engines are fitted with a remote control
lever, make sure that this allows the control to attain
the full movement Max - idle - Choke and Stop.
These positions marked on the handle of the machine
should correspond to the same positions on the governor
control. If full choke and full throttle are not attained,
starting difficulties will be experienced.
1. PNEUMATIC GOVERNOR FOR 2 STROKES
The above engines are fitted with a pneumatic governor
of the type shown in Fig 1. Air vane «B» attached to the
throttle spindle draws air from the flywheel «V». This vane
so under the air pressure from the flywheel tends to close
the throttle until the spring «M» fastened between the
control lever «L» and the vane opposes this movement.
The balance between the two forces giving the desired
throttle opening.
a)
Variable control type (Fig. 2)
The control lever «L» secured to the bracket (Fig 1) may
be moved between the choke position and the stop contact
position. Between the max position (lever against but not
operating the choke) and the min position (lever near but
not touching stop contact), the speed range is obtained.
To increase or decrease the max speed, the spring «M»
is moved to another hole in the lever «L» (Fig 2) by moving
the spring to a hole further away from throttle the speed
is increased and vice versa.
The maximum speed is checked with the lever in the
position at which it contacts the choke control.
NOTE - Always check that the lever will fully close the
choke.
b)
FIXED SPEED EXECUTION
A fixed speed type is available (Fig 3). This being fitted
with a fixed bracket «S» on which is mounted the governor
spring «M».
The speed adjustment is carried out loosening clamp
screw «P» and moving the lever to increase or decrease
the spring tension according to the speed desired.
On this type of governor the choke lever «C» may be a
separate control and there may be a separate stop switch.
Otherwise the lever «L» only operates the choke and the
stop switch. (Fig 4).
Fig. 1
Fig. 2
Fig. 3
Fig. 4
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