Mariner 100, Service Manual, Page: 21 / 391

2A-2 90-13645--2 1095 ELECTRICAL AND IGNITION
Test Sequence
1-A) Check primary input voltage to coils. (See
Test Chart).
1. If voltage readings to coil(s) are BELOW specifi-
cation, proceed with Step 2-A.
2. If voltage readings to coil(s) are WITHIN specifi-
cations, proceed with Step 1-B.
1-B) Check coils for spark. [Connect Spark Gap
Tester (91-63998A1) between coil high voltage
tower and spark plug.]
1. No spark or weak spark. COIL is bad.
2. Spark is OK, proceed with Step 1-C.
1-C) If Step 1-A and 1-B check OK, replace spark
plugs.
If problem exists after replacing spark plugs, proceed
with Step 1-D.
1-D) If Steps 1-A, 1-B, and 1-C check OK, check
ignition timing.
1. If ignition timing does not check to specification
(or a sudden or unexplained timing change
occurs) check trigger advance linkage for loose
and/or broken parts and check trigger magnet
ring (on flywheel hub) for looseness and/or a shift
in position.
2. If ignition checks to specification and engine does
not run or runs poorly, trouble exists with fuel
system or engine mechanical.
2-A) Check switch box “stop” circuit. (See Test
Chart).
1. If reading is BELOW specifications, proceed with
Step 2-B.
2. If reading is ABOVE specifications, the Trigger or
Switch Box is bad (test trigger as outlined in this ser-
vice manual section; if trigger checks OK, replace
switch box and repeat check).
3. If reading is WITHIN specifications, proceed with
Step 3-A.
2-B) Check ignition switch/wiring, as follows:
To prevent engine from starting, remove spark
plug leads from ALL spark plugs and ground
leads to engine.
CAUTION
1. Disconnect ignition switch and stop switch
leads from switch box and isolate the leads.
2. Repeat check in Step 2-A.
3. If reading is still BELOW specification, proceed
with Step 3-A.
4. If reading is WITHIN specification, either the
ignition switch, stop switch, or wiring is bad.
3-A) Check stator low speed and high speed input
to switch box. (See Test Chart).
1. If either the low speed or high speed reading to
switch box is BELOW specification, Stator or
Switch Box is bad (test stator as outlined in this
service manual section; if stator checks to specifi-
cation replace switch box and repeat check).
2. If both the low speed and high speed reading are
WITHIN specification, replace switch box and re-
peat test.