Know Your Unit; Assembly Instructions; Oil And Fuel Information; Starting/Stopping Instructions - MTD MP425 Operator's Manual

KNOW YOUR UNIT

APPLICATIONS
As a trimmer:
• Cutting grass and light weeds.
• Edging
• Decorative trimming around trees,
fences, etc.
Other optional accessories may be used
with this unit.
Starter Rope Grip
On/Off Control
EZ-Link™
Shaft Housing
Cutting Head Shield
Line Cutting
Blade
Cutting Head

ASSEMBLY INSTRUCTIONS

INSTALL CUTTING ATTACHMENT SHIELD
WARNING:
To prevent serious personal injury, never operate the trimmer without the cutting
attachment shield in place.
Use the following instructions if the cutting attachment shield on the unit is not installed. Use only the instructions that
apply to the type of shaft and shield that the unit is
equipped with.
1. Place the cutting attachment shield onto the
shaft housing. Be sure the guard mounting
bracket slides into the slot on the edge of the
cutting shield. Rotate the shield into place,
counterclockwise (Fig. 1). The holes in the guard
mounting bracket and cutting attachment shield
will line up.
2. From inside the cutting attachment shield, push
the square bolt through the hole until the
threaded end protrudes through the guard mounting bracket (Fig. 2).
3. Put the washer on the bolt, then screw the wing nut onto the bolt and tighten.
INSTALLING AND ADJUSTING THE D-HANDLE
1. Remove the screws and bottom clamp piece that were installed on the D-handle
for shipping.
2. Place D-handle the over the shaft housing and onto the bottom clamp (Fig. 3).
Place it a minimum of 6 inches (15.24 cm) from the end of the shaft grip.
3. Start screws with a large Flat-head or T-25 Torx screwdriver. Do not tighten until
the handle adjustments are made.
4. If the D-handle was pre-installed, loosen the screws on the handle just enough to move it.
5. While holding the unit in the operating position (Fig. 14), position the D-handle to the location that provides the best
grip.
6. Tighten the clamp screws evenly, until the D-handle is secure.
OPERATING THE EZ-LINK™ SYSTEM
The EZ-Link™ system enables the use of these optional Add-Ons.
Mach 4® Trimmer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AF720
Hedge Trimmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AH720*
Brushcutter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BC720*
Bladed Pruner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BP720
Blower Trimmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BT720*
Blower Vacuum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BV720
Cultivator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GC720
Lawn Dethatcher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LD720
Edger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LE720*
Pole Saw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PS720
Straight Shaft Trimmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SS725
Snow Thrower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ST720
Turbo Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TB720
* Do NOT use this Add-On with an electric powered unit.
REMOVING THE ADD-ON
1. Turn the knob counterclockwise to loosen (Fig. 6).
2. Press and hold the release button (Fig. 4).
3. While firmly holding the upper shaft housing,
pull the lower shaft housing straight out of the
EZ-Link™ coupler (Fig. 5).
Installing the Add-On
NOTE: To make installing or removing the add-
on easier, place the unit on the ground
or on a work bench.
1. Turn knob counterclockwise to loosen (Fig. 6).
2. While firmly holding the add-on, push it straight into the EZ-Link™ coupler (Fig. 5).
NOTE: Aligning the release button with the guide recess will help installation (Fig. 4).
3. Turn the knob clockwise to tighten (Fig. 6).
For decorative trimming/edging with the line cutting head, lock the release button
into the 90° hole (Fig. 6).
Spark Plug
Muffler
Fuel Cap
Blue Choke Lever
Shaft Grip
Throttle Control
Air Filter Cover
D-Handle
Cutting Mount
Shield Bracket
Square Bolt
Fig. 1
Shaft Grip
Minimum
6 in.
(15.24 cm)
EZ-Link™ Primary Hole
Release Button
Coupler
Upper Shaft
Housing
Guide Recess
Fig. 4
90˚ Edging Hole
(Trimmer Only)
WARNING:
proper oil level in the crank case; it is important and cannot be overemphasized. Check the oil before
each use and change it as needed. See Changing the Oil.
RECOMMENDED OIL TYPE
Using the proper type and weight of oil in the crankcase is extremely
important. Check the oil before each use and change the oil regularly. Failure
to use the correct oil, or using dirty oil, can cause premature engine wear and failure.
Oil Fill Plug
Use a high-quality SAE 30 weight oil of API (American Petroleum Institute) service class SF, SG, SH.
ADDING OIL TO CRANKCASE: INITIAL USE
NOTE: This unit is shipped without oil. In order to avoid damage to the unit, put
oil in the crankcase before you attempt to start the unit.
Your unit is supplied with one 3.04 fluid oz. (90 ml.) bottle of SAE 30 SF, SG, SH oil
(Fig. 7).
NOTE: Save the bottle of oil. It can be used to measure the correct amount during
future oil changes. See Changing the Oil.
1. Unscrew the top of the bottle of oil and remove the paper seal covering the
opening. Replace the top. Next, cut the tip off the funnel spout (Fig. 7).
2. Tip unit so that the back of the engine is facing up in a vertical position.
3. Remove the oil fill plug from the crankcase (Fig. 9).
4. Pour the entire bottle of oil into the oil fill hole (Fig. 8).
NOTE: Never add oil to the fuel or fuel tank.
Primer
5. Wipe up any oil that may have spilled and reinstall the oil fill plug.
Bulb
Check oil before each use and change as needed. Refer to Checking the Oil Level.
RECOMMENDED FUEL TYPE
Old fuel is the primary reason for improper unit performance. Be sure to use fresh,
clean, unleaded gasoline.
NOTE: This is a four cycle engine. In order to avoid damage to the unit, do not
mix oil with gasoline.
Definition of Blended Fuels
Today's fuels are often a blend of gasoline and oxygenates such as ethanol, methanol
or MTBE (ether). Alcohol-blended fuel absorbs water. As little as 1% water in the fuel can make fuel and oil separate or
form acids when stored. Use fresh fuel (less than 60 days old), when using alcohol-blended fuel.
Using Blended Fuels
If you choose to use a blended fuel, or its use is unavoidable, follow recommended precautions:
• Always use fresh unleaded gasoline
• Use the fuel additive STA-BIL® or an equivalent
• Drain tank and run the engine dry before storing unit
Using Fuel Additives
WARNING:
Avoid creating a source of ignition for spilt fuel. Do not start the engine until fuel vapors dissipate.
WARNING:
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.
The use of fuel additives, such as STA-BIL® Gas Stabilizer or an equivalent, will inhibit corrosion and minimize the
formation of gum deposits. Using a fuel additive can keep fuel from forming harmful deposits in the carburetor for up to
six (6) months. 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 gas tank.
FUELING THE UNIT
WARNING:
Never operate the unit without the fuel cap securely in place.
1. Remove the fuel cap (Fig. 10).
2. Place the gas container's spout into the fill hole on the fuel tank (Fig. 10) and fill the
tank.
NOTE: Do not overfill the tank.
3. Wipe up any gasoline that may have spilled.
4. Reinstall the fuel cap.
Washer
5. Move the unit at least 30 ft. (9.1 m) from the fueling source and site before starting the engine.
NOTE: Dispose of the old gasoline in accordance to Federal, State and Local regulations.
Wing
Nut
Fig. 2
WARNING:
Screws (4)
Never operate the unit without the fuel cap securely in place.
D-Handle
WARNING:
starting position when pulling the starter rope (Fig. 12). To avoid serious
injury, the operator and unit must be in a stable position while starting.
STARTING INSTRUCTIONS
Bottom Clamp
1. Check the oil level in the crankcase. Refer to Checking the Oil Level.
Fig. 3
2. Fill the fuel tank with fresh, clean unleaded gasoline. Refer to Fueling the Unit.
NOTE: There is no need to turn the unit on. The On/Off Control is in the ON (I)
position at all times (Fig. 11).
IF COLD... For cold weather conditions (below 40°F), flip the Cold Weather Start
Lever (Fig. 12) down to the start/closed position and continue to step 3.
DO NOT flip this lever down if the temperature is above 40°F.
3. Fully press and release the primer bulb 10 times, slowly. Some amount of fuel
should be visible in the primer bulb (Fig. 12). If fuel can not be seen in the bulb,
press and release the bulb until fuel is visible.
4. With the unit in the starting position, do not squeeze the throttle control (Fig. 13).
Pull the starter rope until unit starts.
IF COLD... For cold weather conditions (below 40°F), flip the Cold Weather Start
Lever back up to the run/open position after the unit has started and
before squeezing the throttle control.
5. Once the unit starts, wait 60 seconds and then squeeze the throttle control.
6. Continue squeezing the throttle control for an additional 30 to 60 seconds to let
the engine warm up. The unit may be used during this time.
IF... The engine does not start, go back to step 3.
IF... The engine stops while squeezing the throttle, go back to step 4.
STOPPING INSTRUCTIONS
1. Release the throttle control and allow the engine to cool down by idling.
2. Press and hold the On/Off Control in the OFF (O) position until the unit comes to a complete stop. (Fig. 11)
HOLDING THE TRIMMER
WARNING: Always wear eye, hearing, foot and body protection to reduce the risk of injury when operating
Lower Shaft this unit.
Housing
Fig. 5
Before operating the unit, stand in the operating position (Fig. 14). Check for the following:
• The operator is wearing eye protection and proper clothing
• With a slightly-bent right arm, the operator's hand is holding the shaft grip
• The operator's left arm is straight, the left hand holding the J-handle
• The unit is at waist level
• The cutting head is parallel to the ground and easily contacts the grass without
the need to bend over
Knob
ADJUSTING TRIMMING LINE LENGTH
Fig. 6
CAUTION: Do not remove or alter the line cutting blade assembly.
Excessive line length will make the unit overheat. This may lead to
serious personal injury or damage to the unit.
The Bump Head™ cutting head allows you to release trimming line without stopping
the engine. To release more line, lightly tap the cutting head on the ground (Fig. 15)
while operating the trimmer at high speed.
NOTE: Always keep the trimming line fully extended. Line release becomes more
difficult when the cutting line gets shorter.
Each time the head is bumped, about 1 inch (25.4 mm) of trimming line releases. A blade in
the cutting head shield will cut the line to the proper length if any excess line is released.
For best results, tap the bump knob on bare ground or hard soil. If you attempt a line release in tall grass, the engine may
stall. Always keep the trimming line fully extended. Line release becomes more difficult when the cutting line gets shorter.

OIL AND FUEL INFORMATION

Overfilling oil crankcase may cause serious personal injury. Check and maintain the
Add fuel in a clean, well ventilated outdoor area. Wipe up any spilled fuel immediately.
Gasoline is extremely flammable. Ignited vapors may explode. Always stop the engine
Remove fuel cap slowly to avoid injury from fuel spray.

STARTING/STOPPING INSTRUCTIONS

Remove fuel cap slowly to avoid injury from fuel spray.
Avoid accidental starting. Make sure you are in the

OPERATING INSTRUCTIONS

Funnel
Spout
Fig. 7
Fig. 8
Oil Fill
Plug
O-Ring
Oil Fill
Hole
Fig. 9
Gas Can Spout
Fuel Cap
Fuel Tank
Fig. 10
OFF (O)
ON (I)
Throttle
Control
Fig. 11
Primer Bulb
Cold Start
Lever
Run/ Open
Close/ Start
Fig. 12
Starting Position
Starter
Rope
Throttle
Control
Fig. 13
Fig. 14
Fig. 15
3