Onan MJA Series Service Manual page 47

45 IGNITION SYSTEM
5. To disassemble the breaker plate assembly, remove the condenser
and points and pull out the plunger and plunger diaphragm .
B. Repair. - Thoroughly clean the gear
and cam assembly. The weights should
move freely in and out without catching in
either end position. Inspect the gear ramp
for notches or other defects.
If
any part of
the cam, weight and gear assembly sticks,
the complete. assembly must be replaced.
Inspect the weight springs, and compare
them against the data in Fig 3.3. E.
If
the
cam is loose on the gear shaft, the com­
DIMENSION
A
1.255"
I.
54 .\
I
~
i
~
·IJ
CJ~
TENSION
IN POUNDS
o
4.0-4.5
..
.;.
plete assembly must be replaced. Clean
FIG 3. 3. E - CENTRIFUGAL
and inspect the bearing surfaces in the
WEIGHT SPRING DATA
breaker plate and gear case; be sure to
clean the oil trickle holes into these bear-
ings. Check the oil spray hole in the gear case to be sure it is open,
Fig 3.10. A. If the breaker points won't maintain the proper gap, check
for excess wear in both the cam and the ignition breaker plunger.
FIG 3.3. F - TIMING MARKS ON TIMING CAM, GEAR,
AND CAMSHAFT
C.Assembly
1. Install springs on the weight assemblies. Install the cam on the
gear shaft, being sure to align the timing marks, (Fig 3.3. F) and
install the cam spring.
2. Install the spacer and thrust washer on the gear shaft assembly, and
install the assembly into the gear case. Match the timing marks on
the timing gear and camshaft gear (Fig 3.3. F).
3. Install the spring and plunger on the end of the
shaft.