Maintenance And Repair Instructions - MTD Yard-Man YM90BC Manual De Instrucciones

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.
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.
FREQUENCY
Before starting engine
Every 10 hours
Every 25 hours
Every 50 hours
LINE INSTALLATION
This section covers both SplitLine™ and standard single line
installation.
Always use original equipment manufacturer 0.105 in. (2.67
mm) replacement line. Other types of line 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 clockwise (Fig. 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 (Fig. 27).
3. Remove spring from the inner reel (Fig. 27).
Outer Spool
Spring
Inner Reel
Bump Knob
4. Use a clean cloth to clean the the inner reel, spring, shaft
and inner surface of the outer spool (Fig. 28).
5. Check the indexing teeth on the inner reel and outer spool
for wear (Fig. 29). If necessary, remove burrs or replace the
reel and spool.
12

MAINTENANCE AND REPAIR INSTRUCTIONS

MAINTENANCE REQUIRED
Fill fuel tank with fresh fuel
Clean and re-oil air filter
Check and clean spark arrestor
Check spark plug condition and gap
Inspect exhaust port and spark arrestor screen for clogging or
obstruction to assure maximum performance levels
Bolt
Fig. 27
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.
Indexing Teeth
NOTE: SplitLine™ can only be used with the inner reel with the
slotted holes. Single line can be used on either type of
inner reel. Use Figure 30 to identify the inner reel you have.
For Use with Single
Line ONLY
REFER TO
Page 8
Page 14
Page 14
Page 15
Page 14
Fig. 28
Fig. 29
For Use with SplitLine™
or Single Line
Slotted
Holes
Fig. 30