Briggs & Stratton MB (18 HP) - Manual (Page 48)

46
Maintenance Instructions CHECKING/SERVICING/
REPLACING/REPAIRING
Spark Plugs
Every 100 hours, remove the spark plugs, inspect,
clean, and reset the gap (or replace with a new
plug). Clean spark plug with a wire brush. If the
electrodes are burned short or pitted, replace the
plug (refer to
Specifications for the proper type of
replacement plug). Check the spark plug gap with a
wire-type feeler gauge and set the gap between
0.028 and 0.032 in. (0.7 and 0.8 mm). Reinstall and
tighten to 17 ft-lb (23 N
· m). Both spark plugs should be
replaced yearly.
Breaker Points
The Briggs & Stratton engine is equipped with elec-
tronic ignition. No breaker points, maintenance, or
adjustments are necessary with this system. Con-
tact an authorized Briggs & Stratton engine dealer in
case of ignition failure.
Fuel Lines and Clamps
Every year, inspect the fuel line from the tank to
engine for deterioration or damage. Also, inspect the
fuel line clamps for tightness. Good preventive
maintenance calls for complete replacement of fuel
lines and clamps every two (2) years.
Blade Brake Action
Check the function of the cutter blade brake by
engaging the blade clutch (PTO), operating the
engine at full throttle, then disengaging the clutch
and measuring how quickly the blades stop. Watch
the rotation of the blade drive shaft as a visual indi-
cation that movement has stopped. If the brake is
working properly, all rotation will stop five (5)
seconds after disengagement of the clutch. If the
brake system malfunctions -- blades do not stop in
five (5) seconds -- repair the brake before operating
the mower.
REPLACING/REPAIRING
IMPORTANT: ALWAYS use genuine factory re-
placement parts. Substitute parts CAN result in
product malfunction and possible injury to the oper-
ator and/or others.
Drive Belts
There are two (2) individual belts on the machine:
•
Engine/PTO Belt
•
Ground Drive Belt
The belts may be removed and replaced using the
procedures described on the following pages.
WARNING
It is important to check and maintain blade
brake action for safe operation of the ma-
chine.
DANGER
To prevent accidental starting of the
engine when replacing parts or repairing
the machine, remove the key from the
ignition switch and disconnect the spark
plug wires.
Belt Locations
Engine/PTO
Belt
Ground Drive Belt