Figure 45
CRANKSHAFT
(Fig. 45)
Take off flywheel nut and remove flywheel. Knock out woodruff
key and pull crankshaft out from open end of crankcase.
In
reassembly; mount flywheel after crankshaft is assembled,
and hand tighten flywheel nut. Flywheel will support crankshaft
for mounting of connecting rod and piston. Flywheel nut is tightened
after gear cover is mounted, and previous to checking end play.
STATOR
PLATE and END PLAY (Fig's. 46, 47) The stator plate functions
as an adapter for the magneto coil as well as a front bearing
support. Since the crankshaft end play is adjusted by means of
the stator plate gaskets, it is advisable not to remove the plate
unless replacement is necessary.
To
remove stator plate, take out four capscrews and tap plate from
inside crankcase with a wooden hammer handle. In reassembly:
Use new gaskets having the same total thickness as those removed.
Torque stator plate capscrews to 18 ft./lbs.
End play is checked after crankshaft, gear cover and flywheel
are mounted. The end play should be .001 to .004
inch with engine cold, and can be determined as
illustrated in Figure 47. Wedge a lever between the flywheel
and crankcase, and move the crankshaft forward and backward against
a dial indicator. If there is too much end play, a corresponding
thickness of gasket will have to be removed from behind stator
plate. Not enough end play and gasket will have to be added.
Figure 46
|
Figure 47
If
new tapered crankshaft main bearings are installed, seat bearings
by alternately striking each end of the crankshaft several sharp
blows with a lead hammer. Then proceed to check crankshaft end play.
After
end play is set; refer to flywheel reassembly paragraphs,
for final instructions on tightening of flywheel nut.
GOVERNOR
OPERATION
Two flyweights are hinged to lugs on the governor gear. Hardened
fingers on the flyweights bear against a thrust sleeve, moving it
back and forth as the flyweights move in or out. The motion of the
thrust sleeve is transmitted through a yoke connected to the governor
lever, which in turn is connected to the carburetor throttle. A
spring connected to the governor lever tends to hold the governor
flyweights to their inner position, also to hold the
carburetor throttle open. As the engine speed increases, centrifugal
force from the flyweights acts against the spring and closes the
throttle to a point where the engine speed will be maintained practically
constant under varying load conditions. This speed can be varied
to suit conditions by adjusting the governor spring tension.
GOVERNOR
ADJUSTMENT (Fig. 48)
The governor rod connection to the carburetor must be very carefully
adjusted for length, otherwise the governor will not function properly
and may cause the engine to surge badly. With the engine at rest,
the governor spring will keep the flyweights in, and the control
rod must be of such length as to hold the carburetor throttle wide
open at that point.
With
the control rod disconnected from the governor lever,
as illustrated in Figure 48, push the rod toward the carburetor
as far as it will go. This will put the carburetor throttle lever
in a wide open position. The governor lever should then be extended
as far as possible in the same direction. Holding both parts in
the above position, the rod should be screwed in or out of the swivel
block on the carburetor, until the bent end of the rod will register
with hole in leve.
Snap
control rod clip in place and tighten locknut against swivel block
on carburetor throttle lever.
|
Figure
48
CORRECT
ENGINE SPEED (Fig. 49)
Engine speed is adjusted by hooking governor spring
in correct hole of governor lever, and then regulating spring
tension by means of an adjusting screw. The governor lever has
7 holes for the governor spring, with the No 1 hole closest to
the fulcrum shaft.
Caution:
Beginning with engine serial No. 5,675,598 the WALBRO
carburetor is standard equipment, with the ZENITH
carburetor optionally used. When readjusting engine speed, use
chart in Fig. 49 relative to the Carburetor Type.
Note:
Two different length adjusting screws are required for the complete
range of operating speeds (see chart).
The
governor lever chart in Figure 49, shows the load and no
load speeds and the corresponding governor spring hole. After
hooking spring into the lever hole relative to the desired load
speed, run the engine without load and regulate the spring
tension by means of the adjusting screw until the
required no load speed is obtained. The governor
spring will have to be disconnected from governor lever each time
screw is turned in or out.
A
tachometer or revolution counter should be used against the crankshaft
to check speed'shile adjusting the governor spring tension. The
engine speed without load will vary from 75 to 180 revolutions
per minute higher than the speed with load. For instance; if the
engine is to operate at 3400 R.P.M. under full load, the speed
with no load will be 3520 R.P.M. Refer to the governor lever chart,
Figure 49 for the variation between load speed and no load
(high idle) speed.
c
|
|
Load
RPM
|
no Load RPM.
|
Hole
No.
|
Load
RPM
|
no
Load RPM
|
Hole
No.
|
|
Zenith
Carburetor
|
|
1600
|
1760
|
1
|
2600
|
2720
|
4
|
|
1800
|
1875
|
2
|
2700
|
2810
|
4
|
|
1900
|
2040
|
2
|
2800
|
2940
|
5
|
|
2000
|
2120
|
2
|
2900
|
3110
|
5
|
|
2100
|
2260
|
2
|
3000
|
3150
|
6
|
|
2200
|
2340
|
3
|
3100
|
3230
|
6
|
|
2300
|
2400
|
3
|
3200
|
3360
|
7
|
|
2400
|
2580
|
3
|
3300
|
3455
|
7
|
|
2500
|
2650
|
4
|
3400
|
3520
|
7
|
|
3500
|
3590
|
7
|
3600
|
3680
|
7
|
|
Walbro
Carburetor
|
|
1600
|
1680
|
1
|
2600
|
2735
|
4
|
|
1800
|
1875
|
2
|
2700
|
2820
|
5
|
|
1900
|
1985
|
2
|
2800
|
2920
|
5
|
|
2000
|
2090
|
2
|
2900
|
3020
|
5
|
|
2100
|
2190
|
2
|
3000
|
3130
|
5
|
|
2200
|
2305
|
3
|
3100
|
3215
|
5
|
|
2300
|
2395
|
3
|
3200
|
3350
|
6
|
|
2400
|
2550
|
4
|
3300
|
3430
|
6
|
|
2500
|
2630
|
4
|
3400
|
3520
|
6
|
|
|
|
|
3500
|
3605
|
6
|
|
|
|
|
3600
|
3695
|
6
|
Figure
49 |
Wisconsin S-10D, S-12D,
S-14D