OPERATING INSTRUCTIONS
OPERATING THE EZ-LINK™ SYSTEM
WARNING:
Before you begin using any attachment, read and understand the manual that came with the attachment. Follow all safety information contained within.
The EZ-Link™ system enables the use of these optional Add-Ons:
Mach 4® Trimmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AF720
Hedge Trimmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AH720
Brushcutter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BC720*
Blower/ Trimmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BT720
Blower Vacuum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BV720
Cultivator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GC720
Edger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LE720
Pole Saw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PS720
Straight Shaft Trimmer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SS725
Snow Thrower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ST720
Turbo Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TB720
*Do NOT use this attachment with an electric powered unit.
Removing the Cutting Attachment or Add-On
EZ-Link
™
Coupler
Release
Button
WARNING:
To avoid serious personal injury and damage to the unit, shut the unit off before removing or installing add-ons.
1. Turn the knob counterclockwise to loosen (Fig. 15).
2. Press and hold the release button (Fig. 13).
3. While firmly holding the upper shaft housing, pull the cutting attachment or add-on straight out of the EZ-
Link™ coupler (Fig. 14).
Installing the Cutting Attachment or Add-On
Primary Hole
CAUTION:
Add-ons are to be used in the primary hole only. Using the wrong hole could lead to personal injury or damage to the unit.
Fig. 13
Guide Recess
NOTE:
Place the unit on the ground or on a work bench to make add-on installation or removal easier.
1. Turn knob counterclockwise to loosen (Fig. 15).
2. While firmly holding the add-on, push it straight into the EZ-Link™ coupler (Fig. 14).
NOTE:
Aligning the release button with the guide recess will help installation (Fig. 13).
3. Turn the knob clockwise to tighten (Fig. 15).
Upper Shaft
Housing
90˚ Edging Hole
(Trimmer Only)
Fig. 14
Lower Shaft
Housing
CAUTION:
Lock the release button in the primary hole and securely tighten the knob before operating this unit.
Knob
Fig. 15
For edging (when using the line head cutting attachment with EZ-Link™ models), lock the release button of the cutting attachment into the 90° edging hole (Fig. 15).
HOLDING THE TRIMMER
WARNING:
Always wear eye, hearing, foot and body protection to reduce the risk of injury when operating this unit.
Before operating the unit, stand in the operating position (Fig. 16). Check for the following:
• The operator is wearing eye protection and proper clothing
• With a slightly-bent right arm, the operator’s right hand is holding the shaft grip
• The operator’s left arm is straight, the left hand holding the handle
Fig. 16
• The unit is at waist level
• The cutting attachment is parallel to the ground and easily contacts the grass without the need to bend over
ADJUSTING TRIMMING LINE LENGTH
The cutting head allows you to release trimming line without stopping the engine. To release more line, lightly tap the cutting attachment on the ground (Fig. 17) while operating the trimmer at high speed.
NOTE:
Always keep the trimming line fully extended.
Line release becomes more difficult as the cutting line becomes shorter.
Fig. 17
Each time the head is bumped, about 1 inch (25.4 mm) of trimming line is released. A blade in the cutting attachment shield will cut the line to the proper length if excess line is released.
For best results, tap the cutting head on bare ground or hard soil. If line release is attempted in tall grass, the engine may stall. Always keep the trimming line fully extended. Line release becomes more difficult as the cutting line becomes shorter.
NOTE:
Do not rest the cutting head on the ground while the unit is running.
Some line breakage will occur from:
• Entanglement with foreign matter
• Normal line fatigue
• Attempting to cut thick, stalky weeds
• Forcing the line into objects such as walls or fence posts
OPERATING INSTRUCTIONS
TIPS FOR BEST TRIMMING RESULTS
• For best trimming results, operate unit at full throttle.
• Keep the cutting attachment parallel to the ground.
• Do not force the cutting attachment. Allow the tip of the line to do the cutting, especially along walls. Cutting with more than the tip will reduce cutting efficiency and may overload the engine.
• Cut grass over 8 inches (200 mm) by working from top to bottom in small increments to avoid premature line wear or engine drag.
• Slowly move the trimmer into and out of the cutting area at the desired height. Move either in a forward-backward or side-to-side motion.
Cutting shorter lengths produces the best results.
• Trim only when grass and weeds are dry.
• The life of your cutting line is dependent upon:
• Proper adherence of explained trimming techniques
• What vegetation is cut
• Where vegetation is cut
For example, the line will wear faster when trimming against a foundation wall as opposed to trimming around a tree.
DECORATIVE TRIMMING
Fig. 18
Decorative trimming is accomplished by removing all vegetation around trees, posts, fences and more.
Rotate the whole unit so that the cutting attachment is at a 30° angle to the ground (Fig. 18).
MAINTENANCE AND REPAIR INSTRUCTIONS
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:
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, 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.
FREQUENCY
Every 40 hours
MAINTENANCE REQUIRED
Every 10 hours Clean and oil air filter
Change 1st 10 hours Change oil
Change oil
Clean spark arrestor and change oil
Check rocker arm to valve clearance and adjust
Check spark plug condition and gap
SEE
p. 6 p. 6 p. 6 p. 6 p. 6 p. 6
REMOVING THE LINE
1. Rotate the bump knob clockwise until all line is inside the cutting head (Fig. 19).
2. Using a flat-head screwdriver, insert the tip into the line dimple and just under the exposed portion of the line (Fig. 20)
3. Pull the line straight out until all line is removed from the cutting head.
LINE INSTALLATION
Always use original equipment manufacturer 0.095 in.
(2.41 mm) replacement line.
1. Align the arrows on the bump knob with the spool cover eyelets, if they are not already (Fig. 21).
2. Using 16 ft. (3.2 m) of 0.095 in. (2.41 mm) replacement line push both ends of the line through the holes in the bump knob until they protrude through the eyelets on both sides of the cutting head. Continue pulling the line until approximately 6 ft. (1.5 m) is visible from both sides of the cutting head. (Fig. 22)
3. Hold the spool cover, turn the bump knob clockwise to wind the line around the spool until about 5 in.
(12.7 cm) is protruding from each side of the cutting head. (Fig. 19)
4. Start the unit and bump the cutting head on the ground until the desired cutting length is achieved.
Excess line will be trimmed off by the line blade.
NOTE:
If the cutting line ends are pulled into the cutting head or the line becomes twisted, refer to Removing the Line.
Bump
Knob
Dimple
Arrows
Fig. 19
Fig. 20
Fig. 21
Flat-Head
Screw Driver
Trimmer
Line
Eyelet
Trimmer line
Fig. 22
5
MAINTENANCE AND REPAIR INSTRUCTIONS
CHECKING THE OIL LEVEL
Oil Fill Plug
WARNING:
To prevent extensive engine wear and damage to the unit, always maintain the proper oil level in the crankcase.
Never operate the unit with a low oil level.
O-Ring
The importance of checking and maintaining the proper oil level in the crankcase cannot be overemphasized.
Check oil before each use:
1. Stop the engine and allow oil to drain into the crankcase.
2. Place the unit on a flat, level surface to get a proper oil level reading.
3. Keep dirt, grass clippings and other debris out of the engine. Clean the area around the oil fill plug before removing it.
4. Remove the oil fill plug.
5. Check the oil level. Oil should be just to the bottom of the threads of the oil fill hole. (Fig. 24).
6. If the level is low, add a small amount of oil to the oil fill hole and recheck (Fig. 24). Repeat this procedure until the oil level reaches the the bottom of the threads in the oil fill hole.
NOTE:
Do not overfill the unit.
NOTE:
Make sure the O-ring is in place on the oil fill plug when checking and changing the oil
(Fig. 23).
CHANGING THE OIL
Add 1.4-1.5 Oz.
(41-44 ml)
Fig. 23
Oil Fill Hole
Fig. 24
Fig. 25
CAUTION:
Wear gloves to prevent injury when handling the unit.
For a new engine, change the oil after the first 10 hours of operation. Change the oil while the engine is still warm. The oil will flow freely and carry away more impurities.
1. Remove the oil fill plug.
2. Pour the oil out of the oil fill hole and into a container by tipping the unit to the side (Fig. 25). Allow ample time for complete drainage.
3. Wipe up any oil residue on the unit and clean up any oil that may have spilled. Dispose of the oil according to Federal, State and local regulations.
4. Refill the crankcase with 2.2 fl.oz. (60 ml) of SAE 30
SF, SG, SH oil.
NOTE:
Use the bottle and spout saved from initial use to measure the correct amount of oil.
The top of the label on the bottle measures approximately 3.4 ounces (100 ml) (Fig. 26).
Check the level (Fig. 24). If the level is low, add a small amount of oil and recheck. Do not overfill (Fig. 24).
5. Replace the oil fill plug.
AIR FILTER MAINTENANCE
Air Filter Cover
Fig. 26
Air Filter Cover
Fig. 27
Fill Level
Air Filter
Cover Tab
Back Plate
WARNING:
To avoid serious personal injury, always turn the unit off and allow it to cool before you clean or service it.
Fig. 28
Cleaning the Air Filter
Clean the air filter every 10 hours of operation. It is an important item to maintain. Failure to maintain the air filter properly can result in poor performance or can cause permanent damage to the engine.
1. Open the air filter cover by pressing the lock tab in and pulling out on the air filter cover (Fig. 27 & 28).
2. Remove the air filter (Fig. 32).
3. Wash the filter in detergent and water (Fig. 29). Rinse the filter thoroughly and allow it to dry.
4. Apply enough clean SAE 30 motor oil to lightly coat the filter (Fig. 30).
5. Squeeze the filter to spread and remove excess oil
(Fig. 31).
6. Replace the air filter into the base plate (Fig. 32).
NOTE:
If the unit is operated without the air filter, you will
VOID
the warranty.
7. Reinstall the air filter cover. Position the two small tabs on the air filter cover into the two slots in the back plate and press the air filter cover down, making sure to align the lock tab with the lock tab slot, until it snaps into place (Fig. 28 & 27).
CARBURETOR ADJUSTMENT
Fig. 29
Fig. 30
The idle speed of the engine is adjustable. An idle adjustment screw is between the air filter cover and the engine starter housing (Fig. 33).
NOTE:
Careless adjustments can seriously damage
Fig. 31
your unit. An authorized service dealer should make carburetor adjustments.
Check Fuel
Old fuel is usually the reason for improper unit performance. Drain and refill the tank with fresh fuel prior to making any adjustments. Refer to Oil and Fuel
Information.
Clean Air Filter
The condition of the air filter is important to the operation of the unit. A dirty air filter will restrict air flow.
This is often mistaken for an out of adjustment carburetor. Check the condition of the air filter before adjusting the idle speed screw. Refer to Air Filter
Maintenance.
Adjust Idle Speed Screw
Back Plate
Air Filter
Idle Ajustment
Screw
Fig. 32
WARNING:
The cutting attachment may spin during idle speed adjustments.
Wear protective clothing and observe all safety instructions to prevent serious personal injury.
If, after checking the fuel and cleaning the air filter, the engine still will not idle, adjust the idle speed screw as follows:
1. Start the engine and let it run at a high idle for a minute to warm up. Refer to Starting/Stopping
Instructions.
2. Release the throttle trigger and let the engine idle. If the engine stops, insert a small phillips or flat blade screwdriver into the hole in the air filter/muffler cover
(Fig. 33). Turn the idle speed screw in,
clockwise
,
1/8 of a turn at a time (as needed) until the engine idles smoothly.
NOTE:
The cutting attachment should not rotate when the engine idles.
3. If the cutting attachment rotates when the engine idles, turn the idle speed screw
counterclockwise
1/8 of a turn at a time (as needed), to reduce idle speed.
Checking the fuel, cleaning the air filter, and adjusting the idle speed should solve most engine problems. If not and all of the following are true:
• the engine will not idle
• the engine hesitates or stalls on acceleration
• there is a loss of engine power
Have the carburetor adjusted by an authorized service dealer.
ROCKER ARM CLEARANCE
Fig. 33
Remove Screws
Fig. 34
Fig. 35
Screw
Rocker Arm Cover
Engine
Cover
Muffler
WARNING:
To avoid serious personal injury, always turn the unit off and allow it to cool before cleaning or servicing it.
Fig. 36
Adjusting Nuts
This requires disassembly of the engine. If feeling unsure or unqualified to perform this, take the unit to an authorized service center.
NOTE:
Inspect the valve to rocker arm clearance with a feeler gauge every 40 hours of operation.
• The engine must be cold when checking or adjusting the valve clearance.
• This task should be performed inside in a clean, dust free area.
1. Remove the two (2) screws on back of the engine cover and the one on the front of the engine cover with a Flat-head or T-25 Torx screwdriver (Fig. 34).
2. Remove the engine cover (Fig. 35).
INTAKE
Rocker Arms
Exhaust
Adjusting Nut
0.003–0.006 in.
(0.076–0.152 mm)
Fig. 37
EXHAUST
Rocker Arm
Feeler
Gauge
3. Disconnect the spark plug wire.
4. Clean dirt from around the spark plug. Remove the spark plug from the cylinder head by turning a 5/8 in. socket counterclockwise.
Fig. 38
Valve Stem
5. Clean dirt from around the rocker arm cover. Remove the screw holding the rocker arm cover with a large flat blade screwdriver or Torx T-25 bit (Fig. 36). Remove the rocker arm cover and gasket.
6. Pull the starter rope slowly to bring the piston to the top of its travel, (known as top dead center). Check that:
• The piston is at the top of its travel while looking in the spark plug hole (Fig. 36)
• Both rocker arms move freely, and both valves are closed
If these statements are not true, repeat this step.
7. Slide the feeler gauge between the rocker arm and the valve return spring. Measure the clearance between the valve stem and rocker arm (Fig. 38). Measure both the intake and exhaust valves.
The recommended clearance for both intake and exhaust is
.003 – .006 in. (.076 – 0.152
mm)
. Use a standard automotive
.005 in. (0.127 mm)
feeler gauge. The feeler gauge should slide between the rocker arm and valve stem with a slight amount of resistance, without binding. Figure 37 and 38 show how to measure the clearance.
8. If the clearance is not within specification: a. Turn the adjusting nut using a 5/16 inch (8 mm) wrench or nut driver (Fig. 38).
• To increase clearance, turn the adjusting nut counterclockwise.
6
MAINTENANCE AND REPAIR INSTRUCTIONS
• To decrease clearance, turn the adjusting nut clockwise.
b. Recheck both clearances, and adjust as necessary.
9. Reinstall the rocker arm cover using a new gasket. Torque the screw to
20–30 in•lb
(2.2–3.4 N•m)
.
10. Check the spark plug and reinstall. See Replacing the Spark Plug.
11. Replace the spark plug wire.
12. Reinstall the engine cover. Check alignment of the cover before tightening the screws.
Tighten screws.
REPLACING THE SPARK PLUG
Use a replacement part number 753-05784 or Champion® RDZ4H spark plug.
The correct air gap is 0.025 in. (0.635 mm). Remove the plug after every 40 hours of operation and check its condition.
1. Stop the engine and allow it to cool. Remove the two (2) screws on back of the engine cover and the one on the front of the engine cover with a Flat-head or T-25 Torx screwdriver (Fig. 34).
2. Grasp the plug wire firmly and pull the cap from the spark plug.
WARNING:
Do not sand blast, scrape or clean electrodes. Grit in the engine could damage the cylinder.
3. Clean dirt from around the spark plug. Remove the spark plug from the cylinder head by turning a 5/8 in. socket counterclockwise.
3. Replace cracked, fouled or dirty spark plug. Set the air gap at
0.025 in. (0.635 mm)
using a feeler gauge
(Fig. 39).
0.025 in.
(0.635 mm.)
Fig. 39
4. Install a correctly-gapped spark plug in the cylinder head. Turn the 5/8 in. socket clockwise until snug.
If using a torque wrench torque to:
110-120 in.•lb. (12.3-13.5 N•m)
Do not over tighten.
SPARK ARRESTOR MAINTENANCE
1. Remove the engine cover. See Rocker Arm Clearance.
2. With a flat blade screwdriver or Torx T-20 bit and a T-25 bit, remove the screws attaching the spark arrestor diverter to the muffler (Fig. 40).
3. Pull the tab on the spark arrestor cover out of the muffler. Remove the spark arrestor cover.
4. Remove the spark arrestor screen from the spark arrestor cover.
Muffler
Spark Arrestor
Screen
5. Clean the spark arrestor screen with a wire brush or replace it.
6. Reinstall the spark arrestor screen, spark arrestor cover and screw.
CLEANING
Diverter
T-25
Screw
WARNING:
To avoid serious personal injury, always turn the unit off and allow it to cool before cleaning or servicing it.
Slot
T-20 Screw
Fig. 40
Use a small brush to clean off the outside of the unit. Do not use strong detergents. Household cleaners that contain aromatic oils such as pine and lemon, and solvents such as kerosene, can damage plastic housing or handle. Wipe off any moisture with a soft cloth.
STORAGE
• Never store the unit with fuel in the tank where fumes may reach an open flame or spark.
• Allow the engine to cool before storing.
• Lock up the unit to prevent unauthorized use or damage.
• Store the unit in a dry, well-ventilated area.
• Store the unit out of the reach of children.
LONG TERM STORAGE
1. Drain all gasoline from the gas tank into a container. Do not use gas that has been stored for more than 60 days. Dispose of the old gasoline in accordance to Federal,
State, and Local regulations.
2. Start the engine and allow it to run until it stalls. This ensures that all gasoline has been drained from the carburetor.
3. Allow the engine to cool. Remove the spark plug and put 5 drops of high quality motor oil into the cylinder. Pull the starter rope slowly to distribute the oil. Reinstall the spark plug.
NOTE:
Remove the spark plug and drain all of the oil from the cylinder before attempting to start the trimmer after storage.
4. Change the oil, referring to Changing the Oil. Dispose of the old oil in accordance to
Federal, State and Local regulations.
5. Thoroughly clean the unit and inspect for any loose or damaged parts. Repair or replace damaged parts and tighten loose screws, nuts or bolts. The unit is ready for storage.
TRANSPORTING
• Allow the engine to cool before transporting.
• Secure the unit while transporting.
• Drain the gas tank before transporting.
• Tighten gas cap before transporting.
ELECTRIC STARTER AND POWER START BIT™ FEATURES
This unit is designed to be started with an optional electric starter or Power Start Bit™ that are sold separately. If choosing to start the unit using one of these features or have questions please contact your local retailer or call
1-800-828-5500 U.S
, (
1-800-668-1238
Canada
), for more information and purchasing. You may also go to
www.troybilt.com
or
www.troybilt.ca
.
Electric Start Feature
7
