Service Manual

111. TROUBLESHOOTING AND TEST PROCEDURES
Generally all gasoline-powered products require
some form of service
or repair during their life-
time. The amount of time and expense involved
in repairing a product can be greatly impacted
by the amount of time required to initially deter-
mine the cause of the difficulty. Therefore, it is
recommended to make these preliminary checks
before proceeding to secondary troubleshooting
procedures.
PRELIMINARY TROUBLESHOOTING
Ignition System
1. Check the ignition switch and wiring
2. Ensure the spark plug is the correct type
3. Check the spark plug for the correct gap,
damaged and excessively carboned
or burnt
electrodes
4. Check the spark intensity.
1. Check the choke position and controls
2. Check the throttle (if so equipped) and gover-
3. Ensure the fuel is fresh, clean and of the
4. Check the fuel filter.
1. Check for housing and element damage
2. Check for dirty element
3. Check for too much or too little oil in the
Fuel System
nor mechanism
proper gas-oil mixture
Air Cleaner
element
Compression
page 111-2)
1. Check the cylinder compression. (Refer to
Crankcase
1. Ensure the crankcase is sealed. (Refer to
page
I11-3)
Spark Intensity
The ignition system can be checked for spark in-
tensity using the spark tester listed in the Special
Tools Section of this manual (Figure
3-1).
Figure 3-1
1. Pull off the spark plug connector and remove
the spark plug.
2. Inspect the spark plug for wear, carbon
deposits and damage. (See Maintenance
Section) Replace the plug
if damaged, burnt,
or fouled.
3. Check for the correct spark plug gap and
adjust,
if necessary, to .8 mm (.032 in) by
bending the outer electrode. Do not pry
against the inner electrode
or the insulator
may be damaged.
4. Attach the spark tester as shown and verify
the tester gap is set at
4.2 mm (.166 in).
5. Pull the starter and observe for spark. THE
SPARK MAY BE DIFFICULT TO SEE
IN
WELL LIGHTED AREAS.
A
CAUTION: Do not test for
spark where gasoline has
been spilled or inflammable vapors may
exist.
A fire could result.
6. If no spark is viewed, refer to the trouble-
shooting chart. (Page
111-4)
ENGINE BRAKE AND IGNITION SWITCH
As a safety measure the engine is designed to
stop within three seconds after the control bar is
released. Release of the control bar grounds the
magneto through the ignition switch to prevent
ignition and allows the spring activated brake
pad to engage the flywheel.
The engine brake and ignition switch are con-
trolled by one common control cable activated
by the control bar on the mower handle. To start
the engine the control bar is raised and held
against the handle. This pulls the brake pad
away from the flywheel and simultaneously de-
presses the plunger on the ignition switch.
THE ENGiNE BRAKE SYSTEM SHOULD
BE
TION OR INJURY MAY RESULT. To troubleshoot
the engine brake and ignition switch:
1. Remove the fuel tank for ease of inspection.
(See Disassembly Instructions page IV-1).
2. Ensure that the brake spring forces the brake
pad against the flywheel when the control
bar is in the ‘STOP” position and that the pad
clears the flywheel when the control bar is in
the ‘START” position.
MAINTAINED
IN PROPER WORKING CONDI-
111-1