Onan MJA Series Service Manual page 49

47
".
,0
IGNITION SYSTE M
2. When a coil passes aU the above-mentioned tests and fails to oper­
ate, it should then be tested on anyone of the popular
make
coil
ahd
WindiIlg testers for Which test data is available.
3.3.4 MJC IGNITION SYSTEM
TheMJC generating plant uses a suppressed battery ignition system
with dual breaker points 'to produce and distribute spark to
4
cylin ­
ders (Fig 3. 3.H).
IGNITION
RESISTOR
TO
CONTROL
DISTRI SUTOR
\
BOX • "­
IGNITION
RESISTOR
TERM.HIGH
WATER TEMP.
BLOCK
CUT OFF SWITCH
FIG 3. 3.H - MJC IGNITION SYSTEM
The ignition system includes 2 ignition coils, distributor with spark ad­
vance and 2 sets of breaker points, and spark plugs. Breaker point set
no. 1 fires cylinders 1 and 4; point set no. 2 fires cylinders 2 and 3.
See Fig 3. 3 .
I.
3.3. 4. 1 Maintenance. - Periodic maintenance of the MJC ignition sys­
tem should include oiling the distributor, cleaning and adjusting the
breaker points, checking ignition timing, cleaning and adjusting the
spark plugs, and general inspection of the ignition system wiring.
A t regular intervals, add 3 to 5 drops of medium engine oil to. the oiler
on the distributor . Add 1 drop of light engine oil to
the
breaker arm
hinge pin and 3 to 5 drops to the centrifugal weight pivots. Wipe grease
lightly on each lobe of the breaker cam. Don't over lubricate the dis ­
tributor.
To adjust the breaker points, remove the distributor cap and rotate the
crankshaft to get maximum breaker gap. The gap should be .017 ­
.022 in. At the same time, inspect the points for dirt or pitting.