Assembly Instructions; Oil And Fuel Information; Starting And Stopping Instructions - MTD MTD5520 Operator's Manual

ASSEMBLY INSTRUCTIONS

This unit comes completely assembled. The saw chain may be loose on the guide bar; refer to Adjusting the Chain
Tension in the Maintenance and Repair Instructions section.
UNPACKING
• Carefully remove the product and any accessories from the box.
• Inspect the product carefully to make sure no breakage or damage occurred during shipping.
• Do not discard the packing material until you have carefully inspected and satisfactorily operated the product.
• If any parts are damaged or missing, please call 1-800-800-7310 (U.S.) or 1-800-668-1238 (Canada) for assistance.
WARNING:
Make sure the stop switch is in the STOP position before inspecting, adjusting, fueling or
performing maintenance on any part of the unit. Failure to do so can result in serious personal injury.
Refer to Starting and Stopping Instructions.
ADDING BAR AND CHAIN LUBRICANT
The guide bar and saw chain require lubrication to minimize friction.
Never starve the guide bar and chain of lubricating oil. Running the
unit without enough oil will decrease cutting efficiency, shorten the
life of the saw chain, cause rapid dulling of the saw chain and
excessive wear to the guide bar from overheating. An insufficient
amount of lubricating oil is evidenced by smoke, guide bar
discoloration or pitch build-up.
WARNING:
Make sure the bar lube reservoir is
always filled. Failure to fill the bar lube reservoir will
cause irreparable damage to the unit.
Fill the bar lube reservoir each time the fuel tank is filled. Only use bar
and chain oil that is formulated to perform over a wide range of
temperatures with no diluting required in the bar lube reservoir. Do
not use motor oil or any other petroleum-based oil.
NOTE: This chain saw comes from the factory with the bar lube reservoir empty. Use the bottle of bar and chain oil that
is included with the unit.
1. Remove the bar lube reservoir cap (Fig. 4).
2. Carefully pour the bar and chain oil into the bar lube reservoir.
3. Replace the bar lube reservoir cap and tighten securely.
4. Wipe off excess oil.
NOTE: Bar lube reservoirs are designed to keep oil slowly flowing onto the chain. This unit will use approximately one
tank of bar and chain oil for every tank of fuel. If the oil flow to the guide bar and chain is too much or too little,
refer to Adjusting the Automatic Oiler in the Maintenance and Repair Instructions section.
NOTE: Do not use dirty, used or otherwise contaminated oils. Damage may occur to the guide bar or chain.
IMPORTANT! Please dispose of oil properly. Consult your local waste authority for information regarding available
disposal options.
FUELING THE ENGINE
This unit is designed to operate on a mixture of unleaded gasoline
and 2-cycle engine oil. Refer to Oil and Fuel Information for complete
mixing instructions and detailed fuel requirements.
1. Turn the unit on its side so that the fuel tank is facing up (Fig. 5).
2. Slowly unscrew and remove the fuel tank cap by turning it anti-
clockwise.
3. Slowly pour the proper fuel/oil mixture into the fuel tank until the
tank is full.
4. Replace the fuel tank cap and turn it clockwise to secure it tightly.
5. Wipe off any spilled fuel.
TESTING THE CHAIN BRAKE
WARNING:
When activating the chain brake, do
so slowly and deliberately. Keep the saw chain from
touching anything; don't let the saw tip forward.
Always test the chain brake before using the unit and periodically
during operation. Follow these instructions to make sure the chain
brake is working correctly:
1. Place the unit on a clear, firm and flat surface.
2. Pull the chain brake lever back to disengage the chain brake.
3. Start the unit. Refer to Starting and Stopping Instructions. Be sure
to maintain a proper grip. Refer to Proper Grip on Handles in the
Operating Instructions section.
4. While the unit is running, squeeze the throttle control trigger to 1/3
throttle and then engage the chain brake by pushing the chain
break lever forward with the left hand (Fig. 6).
The chain should stop moving abruptly. If it does, immediately release the throttle control trigger, turn off the engine and
return the chain brake to the disengaged position. Refer to Starting and Stopping Instructions.
If the chain does not stop when the chain brake is engaged, release the throttle control trigger, stop the engine and have
the unit serviced by an authorized service center.
WARNING:
The chain brake must not move when the engine runs at idle speed. If it does move at
idle speed, refer to the Carburetor Adjustment instructions in the Maintenance and Repair Instructions
section. Avoid contact with the muffler. A hot muffler can cause serious burns.

OIL AND FUEL INFORMATION

CAUTION:
For proper engine operation and maximum reliability, pay strict attention to the oil and fuel
mixing instructions on the 2-cycle oil container. Using improperly mixed fuel can severely damage the engine.
WARNING:
Gasoline is extremely flammable. Ignited vapors may explode. Always stop the engine
and allow it to cool before filling the fuel tank. Do not smoke while filling the tank. Keep sparks and open
flames at a distance from the area.
WARNING:
Remove the fuel cap slowly to avoid injury from fuel spray. Never operate the unit without
the fuel cap securely in place.
WARNING:
Add fuel in a clean, well-ventilated outdoor area. Wipe up any spilled fuel immediately.
Avoid creating a source of ignition for spilt fuel. Do not start the engine until fuel vapors dissipate.
OIL AND FUEL MIXING INSTRUCTIONS
Old fuel and improperly mixed fuel are the two main reasons why the unit
may not run properly. Be sure to use fresh, clean unleaded gasoline and
quality synthetic 2-cycle air-cooled engine oil. Do not use automotive oil or
boat oil; these oils will damage the engine.
Obtaining the Correct Fuel/Oil Mixture
Thoroughly mix the proper amount of 2-cycle engine oil with unleaded
gasoline in a separate fuel container (do not mix them directly in the
engine fuel tank). Use a 40:1 fuel/oil ratio. See the table for specific gas
and oil mixing ratios.
NOTE: One gallon (3.8 liters) of unleaded gasoline mixed with one 3.2 oz.
(95 ml) bottle of 2-cycle oil makes a 40:1 fuel/oil ratio.
When mixing fuel, follow the instructions printed on the oil container. Always read and follow the safety rules relating to
fuel before fueling the unit.
NOTE: Dispose of any old fuel/oil mix in accordance with federal, state and local regulations.
Using Blended Fuels
Today's fuels are often a blend of gasoline and oxygenates such as ethanol, methanol or MTBE (ether). These alcohol-
blended fuels absorb water. As little as 1% water in the fuel can make fuel and oil separate, which leads to the
formation of acids during storage.
If you choose to use a blended fuel, or its use is unavoidable, follow these precautions:
• Always use fresh fuel (less than 60 days old)
• Mix the fresh unleaded fuel with 2-cycle engine oil, as directed above
• Always agitate (shake) the fuel mix before fueling the unit
• Drain the fuel tank and run the engine dry before storing the unit
Using Fuel Additives
The bottle of 2-cycle oil that came with this unit contains a fuel additive that will help inhibit corrosion and minimize the
formation of gum deposits. Using the 2-cycle oil included with this unit is recommended.
If unavailable, use a good 2-cycle oil designed for air-cooled engines along with a fuel additive, such as STA-BIL
Stabilizer or an equivalent. Add 0.8 oz. (23 ml) of fuel additive per gallon of fuel according to the instructions on the
container. NEVER add fuel additives directly to the unit's fuel tank.
NOTE: Never use engine or carburetor cleaner products in the fuel tank or permanent damage can occur.
4
Bar Lube
Bar Lube
Reservoir
Reservoir Cap
Fig. 4
Fuel Tank
Cap
Fuel Tank
Fig. 5
Chain Brake
Fig. 6
UNLEADED GAS 2 CYCLE OIL
1 GALLON US 3.2 FL. OZ.
(3.8 LITERS) (95 ml)
1 LITER 25 ml
MIXING RATIO - 40:1
® Gas

STARTING AND STOPPING INSTRUCTIONS

WARNING:
Only operate this unit in a well-ventilated outdoor area. Carbon monoxide exhaust fumes
can be lethal in a confined area.
WARNING:
Never operate the unit without the guide bar and saw chain properly installed.
BEFORE STARTING THE ENGINE
• Make sure the chain tension is at the desired setting. Refer to Adjusting the Chain Tension in the Maintenance and
Repair section.
• Make sure the bar-retaining nuts are tight to the guide bar cover.
• Make sure the fuel tank is filled with fresh fuel. Refer to Oil and Fuel Information. If the oil and fuel instructions are
not understood, do not attempt to fuel the unit!
• Make sure the bar lube reservoir is filled with bar and chain oil. Refer to Adding Bar and Chain Lubricant in the
Assembly Instructions section.
• Make sure the chain brake is disengaged by pulling the front hand guard / chain brake back toward the front handle
as far as possible. Refer to Testing the Chain Brake in the Assembly Instructions section.
• Make sure the immediate area is clear of any objects or obstructions that could come in contact with the guide bar
and chain.
STARTING THE ENGINE
To help prevent accidental start-ups, this unit has a stop switch,
safety latch, throttle control lockout and a throttle control trigger that
must be used together to start the unit.
1. Move the stop switch down to the RUN position (Fig. 7).
2. Fully press and release the primer bulb 10 times, slowly (Fig. 7).
Some amount of fuel should be visible in the primer bulb. If fuel
cannot be seen in the bulb, press and release the bulb until fuel is
visible.
3. Move the red choke lever to Position 1 (Fig. 8).
4. Place the unit on a firm, flat surface. Crouch in the starting
position and hold the unit firmly, as shown (Fig. 9).
5. Hold down the safety latch and squeeze the throttle control
trigger. While continuing to squeeze both the safety latch and
throttle control trigger, press down the throttle control lockout with
the thumb. Then release the throttle control trigger. This will lock
the throttle into the wide open position.
6. Pull the starter rope 5 times in a controlled and steady motion.
NOTE: This unit uses the AST starting system, which significantly
reduces the effort required to start the engine. You must pull
the starter rope out far enough to hear the engine attempt to
start. There is no need to pull the rope briskly - there is no
harsh resistance when pulling. Do not pull the rope to its
limit, as this may cause the rope to break. Do not let the
rope snap back. Hold the handle and let the rope rewind
slowly. Be aware that this starting method is vastly different
from (and much easier than) what you may be used to.
7. Keep the throttle control trigger locked. Move the red choke
lever to Position 2 (Fig. 8).
8. Keep the throttle control trigger locked. Pull the starter rope 3-5
times in a controlled and steady motion to start the engine.
9. Keep the throttle control trigger locked. Allow the engine to
warm up for 30-60 seconds.
10. Depress and release the throttle control trigger to idle the engine.
11. Move the red choke lever to Position 3 (Fig. 8). The unit is now
ready for use.
IF... The engine does not start, go back to step 2.
IF... The engine fails to start after a few attempts, move the red
choke lever to Position 3 and squeeze the throttle control
trigger. Pull the starter rope 3-8 times in a controlled and
steady motion. The engine should start. If not, repeat.
IF... The unit idles roughly, use a Phillips or standard screwdriver
to turn the idle adjustment screw (Fig. 10) 1/4 to 1/2 turn
clockwise or until the unit idles smoothly.
IF... The saw chain turns while the unit is idling, use a Phillips or
standard screwdriver to turn the idle adjustment screw (Fig.
10) counterclockwise until the saw chain stops and the unit
continues to idle.
IF... The engine starts and idles smoothly, begin the chain brake
test. Refer to Testing the Chain Brake in the Assembly
Instructions section.
IF WARM...If the engine is already warm, perform steps 7 - 11 to
start the unit.
STOPPING THE ENGINE
1. Release the throttle control trigger and allow the engine to return
to idle speed.
2. Move the stop switch up to the STOP position (Fig. 7).
NOTE: It is normal for the chain to coast to a stop once the stop switch is in the STOP position.
NOTE: For emergency stopping, push the chain brake lever / hand guard forward to engage the chain brake and then
move the stop switch up to the STOP position.
Throttle
Stop Switch
Control
Lockout
Safety
Latch
1
2 3
Primer Bulb Throttle Control Trigger
Fig. 7
Red Choke
Lever
1
2
3
Fig. 8
Fig. 9
Idle Adjustment Screw
1
2 3
Fig. 10