Onan MJA Series Service Manual page 53

51
IGNITION SYSTEM
C. Repair. - Clean all disassembled components except the condenser,
breaker points and bushings in light cleaning solvent. When dry, in­
spect all components. Inspect the centrifugal advance component for
signs of wear and replace any that appear WOrn or otherwise damaged.
Inspect the cam and shaft for wear or score marks. If either is scored,
replace it.
To check for excess bearing wear, set the drive shaft into the body and
measure the side play at the top of the cam with a dial indicator. Mount
the indicator on the distributor body, and measure the side play that
occurs when you pull the shaft directly away from the indicator with a
force of about 5 pounds. Side play should be less than. 005 in. If not,
the bearings must be replaced. But, because of the great care that
should be exercised during replacement and special driver required to
correctly size the bearings, ONAN doesn't recommend field replace ­
ment of bronze shaft bearings unless the required equipment is avail­
able. This can be done by an authorized service station.
D. Assembly, Distributor
1. Install the shaft assembly with the upper drive shaft thrust washer
in the distributor body.
2. Install the lower drive
shaft thrust washer and
drive .gear. Install a pin
through the drive gear and
shaft and peen it into place.
3. Check the drive shaft end
play.
It
should be between
.003 in. and. 010 in.
If
end play is too small, tap
the lower end of the dis­
tributor drive shaft lightly
with a soft hammer to in­
crease play.
If it
is too
great, check the thrust
washer installation Or re­
install the gear.
FIG 3. 3. L - CHECKING DISTRffiUTOR
4. Set the centrifugal advance SHAFT END PLAY
weights into place and in ­
stall the cam. Be sure the
pivots on the cam fit into the hole in each weight.
5. Secure the cam with the spring clip and install the weight springs.
6. Install and secure the breaker plate.