Ignition And Battery Charging; Breaker Point Ignition System; Ignition Timing - Onan T260G Service Manual

Ignition and Battery Charging
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BREAKER POINT IGNITION SYSTEM
This section applies to those engines equipped with an
automotive type battery ignition system. Both spark
plugsfire simultaneously, thus the need for a distributor
is eliminated. To maintain maximum engine efficiency,
change the breaker points every 200 hours of operation.
IGNITION TIMING
The timing is preset at the factory. Slight timing changes
can be made by adjusting the point gap.
Breaker Point Replacement and Adjustment
1.
Remove spark plugs.
2. Remove breaker box cover. Rotate crankshaft
clockwise (facing flywheel) until points are fully
open.
3. Remove condenser (screw A) and detach condenser
lead and coil lead (screw B) See Figure 1.
4 .
Remove two Allen screws (C) and lift breaker
assembly from engine.
5.
Replace condenser and point assembly with new
parts and reinstall using above procedure
in
reverse order of removal.
7.
Replace breaker box cover, coil wire, spark plugs,
and spark plug cables.
Continuity Test
As a check
for
proper ignition timing a continuity test
may be performed:
1.
Adjust breaker points
2. Remove blower housing to expose timing marks on
top of gearcase cover and flywheel (Figure 2).
FLYWHEEL TIMING
(TC) MARK
M-1397
FIGURE 2. TIMING MARKS
6. Adjust point gap by rotating crankshaft clockwise
(facing flywheel) by hand until the points are fully
open. Set the point gap (using flat feeler gauge) at
0.020 inch (0.51 mm) by adjusting the socket head
screw (D) inward or outward (Figure 1). A0.020 inch
point gap is equivalent to 20" BTC. Make sure feeler
gauge is clean and free of any grease, oil or dirt.
FIGURE 1. SETTING POINT GAP
3. Rotate flywheel clockwise until
timing mark is
aligned with the proper timing mark (Figure 2)
located on top of gearcase cover. Refer to SPECI-
FICATlONS for proper number of timing degrees.
4. Connect an ohmmeter or a continuity test lamp set
across the ignition breaker points. Touch one test
prod to the coil lead terminal (screw B, Figure 1).
5.
Touch the other test prod to a good ground on the
engine.
6. Turn crankshaft against rotation (counterclock-
wise) until the points close. Then slowly turn the
crankshaft with rotation (clockwise).
7. The lamp should go out or continuity lost just as
the points break which is where ignition occurs. If
timing is early (advanced) the point gap is too
large. If timing is late (retarded) the point gap is
too small. Adjust point gap accordingly.