Maintenance And Repair Instructions - MTD MTD5520 Operator's Manual

OPERATING INSTRUCTIONS
PRUNING
WARNING:
If the limbs to be pruned are above
chest height, hire a professional to perform the pruning.
WARNING:
Use caution when pruning heavy
branches. Falling branches can cause serious injury.
Always wear head protection, plan a safe exit from the
path of falling limbs and stay alert.
Pruning is the process of trimming limbs from a live tree (Fig. 28).
• Work slowly, while maintaining a proper grip and stance.
• Do not cut from a ladder; this is extremely dangerous. Leave this
operation for professionals.
• Do not cut above chest height, as a saw held higher is difficult to control during kickback.
• When pruning trees it is important not to make the finishing cut next to the main limb or trunk until the limb is cut
further out to reduce the weight. This prevents stripping the bark from the main member.
1. Underbuck the branch 1/3 through for the first cut.
2. The second cut should overbuck to drop the branch off.
3. Make the finishing cut smoothly and neatly against the main member so the bark will grow back to seal the wound.
CUTTING SPRINGPOLES
WARNING:
Watch for springpoles; these can
strike the operator, causing serious personal injury.
A springpole is any log, branch, rooted stump, or sapling that is bent
under tension by other wood so that it springs back if the wood
holding it is cut or removed (Fig. 29). On a fallen tree, a rooted stump
has a high potential of springing back to the upright position during
the bucking cut to separate the log from the stump.

MAINTENANCE AND REPAIR INSTRUCTIONS

WARNING:
Before inspecting, cleaning or servicing the unit, stop the engine, wait for all moving parts
to stop, allow the unit to cool, disengage the chain brake and disconnect the spark plug wire to ensure
that the unit cannot start. Failure to follow these instructions can result in serious personal injury or
property damage.
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: Maintenance, replacement or repair of the emission control devices and system may only be performed by an
authorized service center.
A good preventive maintenance program of regular inspection and care will increase the life and improve performance
the unit. This maintenance checklist is a guide for such a program.
Cleaning, adjusting and part replacement may be required, under certain conditions, at more frequent intervals than
those indicated.
CUSTOMER RESPONSIBILITY
MAINTENANCE CHECKLIST
ACTION
Check for loose screws/nuts/bolts and
tighten as needed
Clean the air filter (replace when necessary)
Clean the fuel filter (replace when necessary)
Inspect and clean the spark plug (replace
when necessary)
Inspect and clean the spark arrestor screen
and muffler
Check the bar lube reservoir level (refill
frequently)
Inspect fuel hoses*
Inspect the chain brake components*
Clean the unit and inspect decals
Clean the guide bar groove and oil
passages
Clean the cylinder fins
Check for damaged or worn parts
Check the chain tension (adjust as needed)
Check the sharpness of the chain
Lubricate the sprocket tip
Check the fuel mixture
*If maintenance or replacement are required, have the unit serviced by an authorized service dealer.
6
Pruning Load
First Cut
1/3 Diameter
Finishing Cut
Fig. 28
Springpole
Fig. 29
AFTER EVERY
BEFORE EACH AFTER EACH
10 HOURS OF
USE USE
OPERATION
3
3
3
3
3
3
3
3
3
3
3
3
3
3
WARNING:
Second Cut
touch or adjust the chain while the engine is running.
The saw chain is very sharp; always wear protective
gloves when performing maintenance on the chain.
CAUTION:
too tight upon cooling. Check the "cold tension"
before next use.
ADJUSTING THE CHAIN TENSION
The chain must be tensioned whenever the flats on the drive links
hang out of the bar groove (Fig. 30). Check for proper chain tension
before starting the unit and periodically during operation.
NOTE: A new chain tends to stretch. Check the chain tension
frequently and tighten as required.
1. Stop the engine, wait for all moving parts to stop, allow the unit to
cool, disconnect the spark plug wire and disengage the chain brake.
2. Slightly loosen the bar-retaining nuts (Fig. 31).
3. Hold the guide bar tip up and rotate the chain-tensioning screw
(Fig. 32) clockwise with a standard screwdriver to tension the
chain. The desired tension depends on the temperature of the
chain:
• Cold Chain Tensioning - A cold chain is correctly tensioned
when there is no sag on the underside of the guide bar and the
chain seats snugly against the guide bar with the drive links in
the bar groove.
• Warm Chain Tensioning - During normal operation, the
temperature of the chain will increase. The drive links of a
correctly tensioned warm chain will hang approximately 1/16
inch (1.3 mm) out of the bar groove (Fig. 33).
4. Once adjusted, lift the tip of the guide bar up to check for proper
tension (Fig. 34). If the chain is still too loose, release the tip of the
guide bar and turn the chain-tensioning screw 1/2 turn clockwise.
Repeat this process until the desired tension is achieved.
NOTE: If the chain is too tight, it will not rotate. To loosen the chain,
turn the chain-tensioning screw 1/4 turn counterclockwise.
Ensure that the chain can be turned by hand without binding
(Fig. 35). Also note that the chain will not rotate if the chain
brake is engaged.
5. Hold the tip of the guide bar up and securely tighten the bar-
retaining nuts.
REMOVING/REPLACING THE GUIDE BAR AND CHAIN
Use only a low-kickback saw chain that has met kickback
performance per ANSI B175.1 for this saw. This fast-cutting chain
provides kickback reduction when properly maintained.
NOTE: When replacing the guide bar and chain, use only
manufacturer suggested replacement parts. The use of any
other parts may create a hazard or cause product damage
and will VOID the warranty.
Removing the Old Guide Bar and Chain
1. Make sure the engine is off and the spark plug wire is
disconnected. Disengage the chain brake.
2. Remove the bar-retaining nuts with the supplied multi-purpose
tool. Remove the guide bar cover and guide bar plate by pulling
them straight out (Fig. 31).
3. Remove the guide bar and chain from the mounting surface.
4. Remove the old chain from the guide bar.
Installing the New Guide Bar and Chain
1. Lay out the new saw chain in a loop and straighten any kinks. The
cutters on the top of the guide bar should face toward the guide
bar tip in the direction of chain rotation (Fig. 36). If they face
backward, turn the loop over.
2. Place the chain drive links into the bar groove as shown (Fig. 37).
AFTER EVERY
NOTE: Make sure the chain is correctly installed and the cutters are
20 HOURS OF
facing in the correct direction (Fig. 36).
OPERATION
3. Position the chain so there is a loop at the back of the guide bar.
4. Hold the chain in position on the guide bar and place the loop
around the drive sprocket.
5. Fit the guide bar flush against the mounting surface so that the
two guide bar bolts are in the guide bar slot (Fig. 31).
3
NOTE: Make sure that the chain-tensioning pin is in the chain-
tensioning pin hole (Fig. 38).
6. Replace the guide bar plate so that the bent edges (top and
bottom) are directed away from the chain.
3 7. Replace the guide bar cover and bar-retaining nuts. Tighten the
bar-retaining nuts hand tight.
NOTE: Do not over-tighten the bar-retaining nuts. The guide bar
should still be free to move for chain tension adjustment.
8. Adjust the chain tension. Refer to the Adjusting the Chain Tension
instructions above.
ADJUSTING THE AUTOMATIC OILER
The oiler automatically delivers the proper amount of oil to the guide
bar and saw chain. As the engine speed increases, so does the oil
flow. The amount of oil flowing to the guide bar and saw chain may
be changed by turning the adjustment screw with a small standard
screwdriver. Turn the screw clockwise to decrease oil flow or turn the
screw counterclockwise to increase oil flow (Fig. 39).
Fig. 38
MAINTENANCE AND REPAIR INSTRUCTIONS
To avoid possible serious injury, never
A chain tensioned while warm, may be
Bar-retaining Nuts
Chain Drive
Drive
Sprocket
Chain-tensioning
Pin Hole
Flats
Bar Tip
Fig. 30
Guide
Guide Bar Bolts
Guide Bar Cover
Bar Slot
Guide Bar Plate
Fig. 31
Chain-tensioning Screw
Fig. 32
Approx 1/16"
(1.3 mm)
Bar Tip
Fig. 33
Fig. 34
Fig. 35
Chain
Cutters
Rotation
Links
Fig. 36
Bar Groove
Chain Drive
Links
Fig. 37
Automatic Oiler Adjustment Screw
Fig. 39