Yard-Man YM90, Operator'S Manual

Page: 16 / 82

16
SECTION 7: MAINTENANCE AND REPAIR INSTRUCTIONS
WARNING: To prevent serious injury, never
perform maintenance or repairs with unit
running. Always service and repair a cool
unit. Disconnect the spark plug wire to
ensure that the unit cannot start.
Maintenance Schedule
Perform these required maintenance procedures at the
frequency stated in the table. These procedures should
also be a part of any seasonal tune-up.
NOTE: Some maintenance procedures may require
special tools or skills. If you are unsure about
these procedures take your unit to any non-road
engine repair establishment, individual or
authorized service dealer.
NOTE: Maintenance, replacement, or repair of the
emission control devices and system may be
performed by any non-road engine repair
establishment, individual or authorized service
dealer.
In order to assure peak performance of your engine,
inspection of the engine exhaust port may be necessary
after 50 hours of operation. If you notice lost RPM, poor
performance or general lack of acceleration, this service
may be required. If you feel your engine is in need of this
inspection, refer service to any non-road engine repair
establishment, individual or authorized service dealer for
repair. DO NOT attempt to perform this process yourself
as engine damage may result from contaminants
involved in the cleaning process for the port.
FREQUENCY MAINTENANCE REQUIRED REFER TO
Before starting engine Fill fuel tank with fresh fuel Page 11
Every 10 hours Clean and re-oil air filter Page 18
Every 25 hours
Check and clean spark arrestor
Check spark plug condition and gap Page 19
Page 20
Every 50 hours
Inspect exhaust port and spark arrestor screen for clogging or
obstruction to assure maximum performance levels
Page 19
Line Installation
This section covers both SplitLine™ and standard single
line installation.
Always use Genuine Factory Parts™ 0.095 in. (2.41 mm)
replacement line. Using line other than the specified may
make the engine overheat or fail.
WARNING: Never use metal-reinforced line,
wire, chain or rope. These can break off
and become dangerous projectiles.
There are two methods to replace the trimming line:
• Wind the inner reel with new line
• Install a prewound inner reel
Winding the Existing Inner Reel
1. Hold the outer spool with one hand and unscrew the
bump knob counterclockwise. See Figure 27. Inspect
the bolt inside the bump knob to make sure it moves
freely. Replace the bump knob if damaged.
2. Remove the inner reel from the outer spool. See
Figure 27.
3. Remove spring from the inner reel. See Figure 27.
4. Use a clean cloth to wipe the inner reel, spring, shaft,
and inner surface of the outer spool. See Figure 28.
Figure 27
Figure 28
Inner Reel
Spring
Outer Spool
Bump Knob
Bolt