!
tion will be
erratic. Work the arm back and
forth
several
times
by
hand
while the engine is idle. If
either
of
these
conditions exist,
determine the cause and adjust or
replace parts as needed.
PROCEDURE
1. Adjust the carbutetor main
jet
forthe best fuel
mixture
while
operating
the
plant
with a
full rated
load
connected,
2. Adjust
the carburetor idle needle with no load
connected.
3, Adjust the length of
the
governor
linkage.
4. Check the
governor
linkage
and throttle shaft
for
binding or
excessive looseness.
5.
Adjust the
governor
spring
tension
for
rated
speed
at no load operation
(booster tempotarily discon-
nected).
6,
Adjust the
govemor sensitivity.
7.
Recheck
the
speed adjustme[t.
8. Set the carburetor throttle
stop screw.
9.
Adjust booster (where used).
Linkoge: The engine
starts at wide
open
throttle.
The
length
of
the
linkage cofftecting
the
governo!
arm to
the
throttle
arm is adjusted by rotating
the ball
joint
hous-
ing. Adjust the
length so that with the engine
stopped
and tensioo
on the
governor
spring, the stop
on the
carburetor throttle lever
is
1,/32
inch from the carburetor
stop boss. This setting
allows irnrnediate control
by the
governor
after starting
and synchronizes travel
of the
governor
alm and the throttle shaft.
Speed Adiustrneni:
The speed
at which the engine
operates is determined by
the tension applied
to the
governor
spring.
Increasing
spring
tension
increases
engine
speed.
Decreasing
tension decreases elrgine
speed.
The no-load speed
of
the engine
should be
slightly higher than the
speed
requirements
of the
connected load.
For example:
If
the
connected
load is to
turn
at 1800
rpm,
set the
no-load
speed
of the engine at 1875 rprn
(approx.
).
Check
the
speed
with a tachometer.
lf
a speed
adjustrnent is
needed, turn the speed adjust-
ing
rlut in to increase the speed
or out to dectease the
speed. See
Figure 11.
SENSITIVITY ADJUSTMENT
The engine
speed drop from
no-load
to full-load
should
ttot
be less than
60rpm.
Check the
engine speed
with
no-load
connected,
and again after
connecting full-load.
The sensitivity
of the
governor
depends
upon the
posi-
tion of the arm end
of
the
goveinor
spring. A series
of
holes
irt the
govelnor
arm provides fot
adjustment.
To
increase sensitivity,
rnove the spring
toward the
gover-
nor shaft.
To dectease sensitivity,
move the
spring
toward the
linkage
end
of the
governor
arm.
If
the setting
is
too
sensitive,
a hurting condition
(altemate increase aod decrease
in engine speed)
will
result,
If
the setting
is
not sensitive
enough,
the
speed
valiation between
no-load and full-load
conditions will
be too
great,
Therefore,
the corlect sensitivity will
result
in
the
most stable speed regulation
without
causing
a surge condition.
Al.ways recheck
the speed
adjustment after a sensi-
tivity adjustrnerlt,
Increasing
sensitivity
will cause a
slight decrease
in speed
and will lequire a slight
increase i!'t the
governor
spring
tensioo,
SPEED
BOOSTER
ADJUSTMENT
Afier
satisfactory
performance
under various
loads is
attained
by
governor
adjustments
without
the booster,
connect the booster. Connect
the
extemal booster
spring
to
the
bracket
on the
governor
linkage. With the
plant
operating
at no-load, slide
the bracket
on the
governor
linkage
to a
position
where there
is no
tension
on
the extelnal sprilg.
Apply
a full rated electrical
load
to
the
generator.
The
output
voltage should stabilize
at nearly the
same
ieading
at fullload
as for
no-load opetation. The speed
may remain
about the same
o! increase when
the load
is applied,
resulting in L
ot 2heftz higher
than the no-
load
frequency (lhertz
is equal to
60rpn}
If
the rise
in ftequency
is more than
2 hertz, lessen the
interflal
spring
tension. If
there
is a
drop
in frequency,
increase
the internal
booster spring
tension. To increase
the
te[sio[, pull
out the spri[g
bracket and
move the
pin
to
a different hole.
With the booster
disconnected,
a maximum
drop of
5hertz from
oo-load to full-load
is norrnal. With the
booster
in operation, a
maximum increase
of 2 hertz
from
no-load to 2/3
load is normal. A drop
of thertz
at
l/4
load, is permissible, giving
an overall spread
of
3
hertz
maximum.
TAPPET
ADJUSTMENT
The engine
is equipped with adjustable
tappets. To
make a
valve adjustment,
remove the valve
covers.
Crank
the engine slowly
by
hand until the
left hand
intake valve, when facing
the flywheel,
opens and
closes. Co[tinue
about 1,/4 turn
u[til the
mark o'l the
flywheel
and the TC
mark on the
gear
cover
are
in
line. This should place
the left hand piston
in the
necessary
position
to
obtain correct
valve adjustment.
Cotrect valve clearances
ate
.003
for
intake and
.010 for
exhaust-
For each
valve, the
gauge
should
just
pnss
between the
valve stem and
valve tappet (Figurc 12).
To correct the
valve clearance,
turn the adjusting
screw
as needed
to obtain the right
clearance. The screw
is
self-locking.
To
adjust the
valves
on
the right
hand
cylinder, crank
the engine
over
one complete revolution
and again
line
up
the mark
on the flywheel
and the TC rnark
on
the
gear
cover.
Then follow the
adjustment given
fot the
valves
of the left hand
cylinder.
20
To Next Page
Loading...
Need help?
General
