Toro 51903, 51904, 51906, 51907 Operator's Manual

16” & 18” Gas
Trimmer
Model No. 51903 — 790000001 & Up Model No. 51904 — 790000001 & Up Model No. 51906 — 790000001 & Up Model No. 51907 — 790000001 & Up
16” & 18” Gas
FORM NO. 3319–144 REV A
Modèle No. 51903 — 790000001 et suivants Modèle No. 51904 — 790000001 et suivants Modèle No. 51906 — 790000001 et suivants Modèle No. 51907 — 790000001 et suivants
16” & 18” Gas
Recortadora
Modelos N. 51903 — 790000001 y siguientes Modelos N. 51904 — 790000001 y siguientes Modelos N. 51906 — 790000001 y siguientes Modelos N. 51907 — 790000001 y siguientes
Operator ’s Manual Manuel de l’Utilisateur
Manual del Usuario
WARNING:
The engine exhaust from this product
contains chemicals known to the State of
California to cause cancer, birth defects,
or other reproductive harm.
AVERTISSEMENT:
Les gaz d’échappement du moteur de ce
produit contiennent des produits
chimiques reconnus dans l’état de
Californie comme cancérigènes,
responsables de malformations
congénitales, ou comme nocifs à l’égard
des fonctions de la reproduction.
ADVERTENCIA:
El escape del motor de esta herramienta contiene productos químicos que según
la información del Estado de California
producen cáncer, defectos congénitos u
otros riesgos reproductivos.
Figures–Figuras
1
1
English
1. Model and serial number decal location
Français
1. Emplacement des numéros de modèle et de série
3
4
Español
1. Ubicación de la calcomanía con el modelo y el número de serie
2
Printed in USA
The Toro Company – 1996, Rev. 1997
All Rights Reserved
i
5
7
8
6
ii
9
10
m-2912
2
11
1
English
1. Screw
2. Full choke position
3. Choke lever
Français
1. Vis
2. Position entièrement fermée
3. Levier du starter
Español
1. Tornillo
2. Posición de obturación total
3. Palanca del obturador
3
4
5
4. Run position
5. Partial choke position
4. Position de marche
5. Position partiellement fermée
4. Posición de funcionamiento
5. Posición de obturación parcial
1
English
1. Primer bulb
Français
1. Pompe d’amorçage
Español
1. Perilla de cebado
1
iii
12
1
2
English
1. Starter rope 2. Throttle trigger
Français
1. Corde du lanceur 2. Gâchette de commande des gaz
Español
1. Cuerda de arranque 2. Gatillo del acelerador
14
15
13
English
1. Stand
Français
1. Support
Español
1. Soporte
1
iv
16
17
18
19
20
v
21
22
24
25
23
26
1
English
1. Air filter
Français
1. Filtre à air
Español
1. Filtro de aire
vi
27
1
30
2
3
4
28
29
English
WALBRO CARBURETOR
1. Throttle lever
2. Idle speed screw
Français
CARBURATEUR WALBRO
1. Levier d’accélérateur
2. Vis de régime de ralenti
3. Pointeau de richesse de haut régime
Español
CARBURADOR WALBRO
1. Palanca del acelerador
2. Tornillo de ajuste de la velocidad en ralentí
3. Aguja de ajuste de la mezcla de alta velocidad
3. High speed mixture needle
4. Idle speed mixture needle
4. Pointeau de richesse de ralenti
4. Aguja de ajuste de la mezcla de velocidad en ralentí
vii
1
31 32
2
3
4
English
ZAMA CARBURETOR
1. Throttle lever
2. Idle speed screw
Français
CARBURATEUR ZAMA
1. Levier d’accélérateur
2. Vis de régime de ralenti
3. Pointeau de richesse de haut régime
Español
3. High speed mixture needle
4. Idle speed mixture needle
4. Pointeau de richesse de ralenti
.020 in
(0.5 mm)
1
33
CARBURADOR ZAMA
1. Palanca del acelerador
2. Tornillo de ajuste de la velocidad en ralentí
3. Aguja de ajuste de la mezcla de alta velocidad
4. Aguja de ajuste de la mezcla de velocidad en ralentí
English
1. Muffler mounting bolts
Français
1. Boulons de montage du silencieux
Español
1. Pernos de montaje del silenciador
viii
34 35
1
1
English
1. Inlet port
Français
1. Ouverture d’entrée
Español
1. Orificio de admisión
English
1. Muffler gasket
Français
1. Joint du silencieux
Español
1. Junta del silenciador
ix
Contents
Introduction 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fueling And Before Operating 2. . . . . . . . . .
While Operating 3. . . . . . . . . . . . . . . . . . . . .
Maintenance And Storage 3. . . . . . . . . . . . .
Safety and Instruction Decals 4. . . . . . . . . . .
Symbol Glossary 4. . . . . . . . . . . . . . . . . . . .
Assembly 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing The D-handle 5. . . . . . . . . . . . . . .
Installing The String Guard 5. . . . . . . . . . . .
Before Starting 5. . . . . . . . . . . . . . . . . . . . . . . . . .
Oil And Fuel 5. . . . . . . . . . . . . . . . . . . . . . .
Mixing Oil And Fuel 7. . . . . . . . . . . . . . . . .
Operation 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting/Stopping 7. . . . . . . . . . . . . . . . . . . .
Adjusting The Trimming Line Length 8. . . .
Page
Introduction
Thank you for purchasing a Toro product. All of us at Toro want you to be completely satisfied
with your new product, so feel free to contact your local Authorized Service Dealer for help with service, genuine Toro parts, or other information you may require.
Whenever you contact your Authorized Service Dealer or the factory, always know the model and serial numbers of your product. These numbers will help the Service Dealer or Service Representative provide exact information about your specific product. You will find the model and serial number decal located in a unique place on the product (Fig. 1).
For your convenience, write the product model and serial numbers in the space below.
Decorative Trimming 8. . . . . . . . . . . . . . . . .
Maintenance 8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance Schedule 8. . . . . . . . . . . . . . . .
Line Installation 8. . . . . . . . . . . . . . . . . . . . .
Installing A Prewound Reel 9. . . . . . . . . . . .
Air Filter Maintenance 10. . . . . . . . . . . . . . . .
Carburetor Adjustment 10. . . . . . . . . . . . . . . .
Replacing The Spark Plug 11. . . . . . . . . . . . .
Inspecting/Cleaning The Muffler 12. . . . . . . .
Cleaning 12. . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 13. . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 14. . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine 14. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive Shaft & Cutting Head 14. . . . . . . . . . .
Cold Engine Torque Specifications 14. . . . . .
California Emission Control Warranty Statement 15
Warranty 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Model No.
Serial No.
Read this manual carefully to learn how to operate and maintain your product correctly. Reading this manual will help you and others avoid personal injury and damage to the product. Although Toro designs, produces and markets safe, state-of-the-art products, you are responsible for using the product properly and safely. You are also responsible for training persons who you allow to use the product about safe operation.
The Toro warning system in this manual identifies potential hazards and has special safety messages that help you and others avoid personal injury, even death. DANGER, WARNING and CAUTION are signal words used to identify the level of hazard. However, regardless of the hazard, be extremely careful.
EN–1
DANGER signals an extreme hazard that will cause serious injury or death if the recommended precautions are not followed.
WARNING signals a hazard that may cause serious injury or death if the recommended precautions are not followed.
Fueling And Before Operating
1. Gasoline is extremely flammable and its vapors
can explode if ignited. Always stop the engine and allow it to cool before filling the fuel tank. Do not smoke while filling the fuel tank. Keep sparks and open flames away from the area.
CAUTION signals a hazard that may cause minor or moderate injury if the recommended precautions are not followed.
Two other words are also used to highlight information. “Important” calls attention to special mechanical information and “Note” emphasizes general information worthy of special attention.
Safety
Note: For users on U. S. Forest Land and
in the states of California, Maine, Oregon and Washington. All U.S.
Forest Land and the state of California (Public Resources Codes 4442 and
4443), Oregon and Washington require, by law that certain internal combustion engines operated on forest brush and/or grass-covered areas be equipped with a spark arrestor, maintained in effective working order, or the engine be constructed, equipped and maintained for the prevention of fire. Check with your state or local authorities for regulations pertaining to these requirements. Failure to follow these requirements could subject you to liability or a fine. This unit is not
factory equipped with a spark arrestor. If these items are required in
your area, ask your dealer to install the
Optional Accessory Part #180030 Spark Arrestor Kit.
2. Store gasoline and fuel only in containers
designed and approved for the storage of such materials.
3. Pressure can build up in the fuel tank. Loosen
the fuel tank cap slowly to relieve any pressure in the tank.
4. Add fuel in a clean, well-ventilated area. Wipe
up any spilled fuel immediately. If fuel has been spilled, allow it to dry completely before starting the engine.
5. Move the trimmer at least 10 ft (3 m) from the
fueling point before starting the engine.
6. Thoroughly inspect the trimmer for loose or
damaged parts before each use. Do not use until adjustments or repairs are made.
7. Avoid accidental starting. Be in the starting
position whenever pulling the starting rope.
8. Keep all bystanders, especially children, and pets
at least 33 ft (10 m) away from the area.
9. Carefully inspect the areas to be cut. Remove all
debris that could become entangled in the string or blade. Also remove any objects that could be thrown during cutting.
10. Before starting, make sure the string head is not
in contact with anything.
11. Always remain alert. To prevent injury to
yourself and others, do not operate this trimmer if you are fatigued.
12. Do not operate the unit while under the influence
of drugs, alcohol or medication.
EN–2
While Operating
1. Wear safety glasses or goggles at all times when
operating this trimmer.
2. Dress properly. Do not operate this trimmer
when barefoot or wearing open sandals. Always
wear sturdy, rubber-soled footwear. The use of
gloves, ear/hearing protection and long pants are
recommended.
3. Do not wear loose fitting clothing or articles
such as scarves, strings, chains, ties, etc. because
they could get drawn into the air intake. Also
make sure long hair does not get drawn into the
air intake.
4. Keep hands, face, and feet away from all moving
parts. Do not attempt to touch or stop the string
when it is rotating.
5. Do not touch the muffler or cylinder. These parts
get extremely hot from operation and remain hot
for a short time after the equipment is turned off.
9. Use the right tool. Do not use this trimmer for
any job except that for which it is intended.
10. Do not force the tool at a rate faster than the rate
at which it is able to cut effectively.
11. Do not overreach. Keep proper footing and
balance at all times.
12. Do not operate the engine faster than the speed
necessary to cut, trim or edge. Do not run the engine at high speed when not cutting.
13. The string guard must be in place at all times
while operating the trimmer.
14. Do not extend the trimming line beyond the
length specified in this manual.
15. Always stop the engine when cutting is delayed
or when walking from one cutting location to another.
6. Always hold the trimmer with both hands when
operating. Keep a firm grip on both the front and
rear handles or grips.
7. Operate this trimmer only in a well-ventilated
area -outdoors. Carbon monoxide exhaust fumes
can be lethal in a confined area.
8. If the unit strikes or becomes entangled with a
foreign object, stop the engine immediately and
check for damage. Repair any damage before
further operation is attempted. Do not operate
the trimmer with loose or damaged parts.
Maintenance And Storage
1. Use only genuine Toro replacement parts when
servicing this trimmer. These parts are available from your authorized dealer. The use of non-standard parts, or other accessories or attachments not approved for this trimmer, could result in serious injury to the user or damage to the trimmer and void your warranty.
2. Lock up and store the trimmer in an appropriate
and dry location to prevent unauthorized use and damage. Keep unit out of the reach of children.
EN–3
Safety and Instruction Decals
(
)
Safety decals and instructions are easily visible to the operator and are located near any area of potential danger. Replace any decal that is damaged or lost.
ON ENGINE
(Part No. 92-3332)
ON GAS TANK
Part No. 92-3334
Symbol Glossary
ON BOOM
(Part No. 92-3328)
Hot surface
Stay a safe distance from the machine
Read operator’s manual
Fuel Oil
Wear eye and hearing protection
Thrown or flying objects–Whole body exposure
For service information, call: 1–800–237–2654
EN–4
Assembly
Note: Failure to follow these assembly
instructions may cause flex shaft failure.
Model 51906
1. Slide the string guard onto the guard mount
above the string head assembly. Align the screw holes in the string guard with the screw holes in the string assembly (Fig. 6).
Installing The D-handle
1. Push the D-handle down over the boom (Fig. 2).
2. Install the bolt, washer and wing nut and tighten
(Fig. 2).
Installing The String Guard
POTENTIAL HAZARD
Foreign objects can be thrown by trimmer.
WHAT CAN HAPPEN
Contact with thrown objects can cause
personal injury.
HOW TO AVOID THE HAZARD
Never operate the trimmer without the
string guard in place.
Model 51903
1. Place the string guard onto the boom above the
clamp assembly (Fig. 3).
2. Place the three hex nuts into the recessed holes
on top of the guard (Fig. 7).
3. Install the screws into the holes from the bottom
of the guard. Tighten the screws (Fig. 8).
Before Starting
Oil And Fuel
THIS ENGINE IS CERTIFIED TO OPERATE ON UNLEADED GAS AND OIL MIXTURE.
Note: BE SURE TO READ THESE
INSTRUCTIONS CAREFULLY BEFORE ATTEMPTING TO START OR OPERATE THIS UNIT. Using old or improper oil or fuel, or improperly mixing the oil and fuel can cause engine damage. This type of damage will void the engine warranty.
2. Push the string guard down to the top of the
string head assembly and then rotate the string
guard to the proper position (Fig. 4). The string
guard is in the correct position when the string
guard points toward the engine, and the holes in
the string guard line up with the holes in the top
of the string head assembly.
3. Install the screws with a Phillips screwdriver
(Fig. 5).
EN–5
POTENTIAL HAZARD
In certain conditions gasoline is extremely
flammable and highly explosive.
POTENTIAL HAZARD
Gasoline/oil mixture contains petroleum
distillate.
WHAT CAN HAPPEN
A fire or explosion from gasoline can burn
you, others, and cause property damage.
HOW TO AVOID THE HAZARD
Use a funnel and fill the fuel tank outdoors,
in an open area, when the engine is cold. Wipe up any gasoline that spills.
Do not fill the fuel tank completely full.
Add gasoline to the fuel tank until the level is 1/4” to 1/2” (6 mm to 13 mm) below the bottom of the filler neck. This empty space in the tank allows gasoline to expand.
Never smoke when handling gasoline, and
stay away from an open flame or where gasoline fumes may be ignited by a spark.
Store gasoline in an approved container
and keep it out of the reach of children.
Never buy more than a 30-day supply of
gasoline.
Recommended Oil Type
WHAT CAN HAPPEN
Gasoline/oil mixture can be harmful or
fatal if swallowed. It can also irritate your skin.
HOW TO AVOID THE HAZARD
Do not drink gasoline/oil mixture.
Avoid prolonged contact with skin. Wash
thoroughly after handling.
Do not reuse oil bottle.
IMPORTANT: If gasoline/oil mixture is swallowed, do not induce vomiting. CALL PHYSICIAN IMMEDIATELY.
Recommended Fuel Type
Use clean, fresh, unleaded gasoline that is less than 60 days old.
Note: Alcohol blended fuel absorbs moisture
(water). As little as 1% moisture in the fuel can cause fuel and oil to separate and form acids when stored.
An 8oz. (0.24 liter) bottle of 2-cycle engine oil is included with your product.
TORO 2-cycle oil is recommended for this outdoor power tool. If another brand of 2-cycle oil is used, make sure it is high quality oil, formulated for 2-cycle, air-cooled engines.
If this type of fuel must be used, use
fresh fuel, (less than 60 days old) and mix according to the mixing instructions.
Definition Of Blended Fuels
Today’s fuels are often a blend of gasoline and one or more oxygenates such as ethanol, methanol or MTBE (ether).
Use Of Blended Fuels
If you choose to use a blended fuel or its use is unavoidable, the following precautions are recommended.
EN–6
1. Always use fresh fuel mix per your operator’s
manual.
2. Use the special additive STA-BIL or an
equivalent.
3. Always agitate the fuel mix before fueling the
unit.
4. Drain the tank and run the engine dry before
storing the unit.
Use Of Fuel Additives
The use of fuel additive, such as STA-BIL Gas Stabilizer or an equivalent, will inhibit corrosion and minimize the formation of gum deposit. Add 0.8 oz (23 ml) per gallon of fuel per instructions on container. NEVER add fuel additives directly to the unit’s fuel tank. Using a fuel additive can keep fuel
fresh for up to six (6) months.
POTENTIAL HAZARD
Gasoline contains gasses that can build up
pressure inside a gas tank.
WHAT CAN HAPPEN
Fuel can be sprayed on you when removing
gas cap.
HOW TO AVOID THE HAZARD
Remove fuel cap slowly to avoid injury
from fuel spray.
Operation
Starting/Stopping
1. Mix oil with gas and fill fuel tank with fuel/oil
mixture — Per instructions on page 7.
Mixing Oil And Fuel
Note: For proper engine operation and
maximum reliability, pay strict attention to the oil and fuel mixing instructions on the 2-cycle oil container. Use a 32:1 fuel/oil ratio when you use 2-cycle oil. Using improperly mixed fuel can severely damage the engine.
Thoroughly mix the proper ratio of 2-cycle engine oil with unleaded gasoline in a separate fuel can, 32:1. Do not mix them directly in the engine fuel tank. See
the following table for specific gas and oil mixing ratios.
32:1 GAS/OIL Mixing Chart
Gasoline Oil
1 US gallon 4.0 oz. (3.8 liters) (118 ml) 1 liter 30 ml
2. Fully press and release the primer bulb 5 to 7
times. See Fig. 10 for the primer bulb location.
3. Place the choke lever in the full “choke”
position. See Fig. 11.
4. With the unit on the ground, squeeze the throttle
trigger fully and pull the starter rope briskly (Fig. 12) until the engine sounds like it wants to run. (Normally 2 to 5 pulls).
5. Place the choke lever in the “partial” choke position (Fig. 11). Pull the starter rope briskly 1 to 3 times to start the engine (Fig. 12).
6. If the engine does not start, repeat steps 3 through 5.
7. After the engine warms up for 5 to 10 seconds, place the choke lever in the “run” position (Fig. 11).
8. To stop the engine, hold the kill switch in the “off” position until the engine stops (Fig. 9).
EN–7
Note: When storing the unit or when setting
unit down between uses, place the unit flat on the floor so it sits on its stand instead of hanging it by the guard or the cutting head (Fig. 13).
Note: Always keep the trimming line fully
extended. Line release becomes more difficult as cutting line becomes shorter.
Each time the head is bumped, about 1 inch (25.4 mm) of trimming line is released. A blade in the weed guard will cut the line to the proper length if excess line is released.
Adjusting The Trimming Line Length
Your trimmer is equipped with a bump head that allows the operator to release more trimming line without stopping the engine. To release additional line, lightly tap the trimming head on the ground (Fig. 14 – Model 51903, Fig. 15 – Model 51906) while operating the trimmer at high speed.
For best results, tap the head on bare ground or hard soil. If line release is attempted in tall grass, the engine may stall.
Decorative Trimming
Decorative trimming is accomplished by removing all vegetation around trees, posts, fences, etc. (Fig. 16 – Model 51903, Fig. 17 – Model 51906).
Maintenance
Maintenance Schedule
These required maintenance procedures should be performed at the frequency stated in the table to ensure that your unit continues to meet the 1995 California emission regulations. They should also be included as part of any seasonal tune-up.
Frequency Maintenance Required Refer to:
Before starting engine Fill fuel tank with correct oil and fuel mixture. Page 7 Every 10 hours Clean and re-oil air filter. Page 10 Every 25 hours Inspect and clean muffler. Page 12 Every 50 hours Check spark plug condition and gap. Page 11
Line Installation
The trimming line may be replaced by two different methods — rewinding the existing reel or installing a prewound reel.
Rewinding The Existing Reel
To rewind the existing reel you must:
1. Check for the correct line size.
2. Remove the existing reel and spring.
3. Wind the existing reel with the new line.
4. Reinstall the existing reel and spring.
EN–8
The Correct Line To Use
POTENTIAL HAZARD
Use of improper line could cause line to
break and be thrown in operator’s or bystander’s direction.
WHAT CAN HAPPEN
Use of improper line could result in serious
personal injury.
Winding The Existing Reel
1. Take approximately 25 ft (7.6 m) of new trimming line, loop it into two equal lengths. Insert each end of the line through one of the two holes in the inner reel (Fig. 22). Pull the line so that the loop is as small as possible.
2. Wind the lines, in even and tight layers, onto the reel (Fig. 23). Wind the line in the direction indicated on the inner reel. Be sure not to overlap the two ends of the line.
HOW TO AVOID THE HAZARD
Use only Toro approved replacement
monofilament line.
Do not use any type of wire or other
string–like substance. Do not use metal-reinforced line.
It is very important to use the correct size line. A line with a diameter of .080 inches (2.03 mm) must be used. The engine may overheat and fail if you use
a larger line.
Removing The Existing Reel
1. Stop engine and wait for all moving parts to
stop. Pull wire off spark plug.
2. Hold the outer spool with one hand and unscrew the Bump Knob counterclockwise (Fig. 18). Inspect the captured bolt inside the Bump Knob to make sure it moves freely. Replace the Bump Knob if it is damaged.
Note: Place your index finger between the
two lines to stop the lines from overlapping.
Note: Failure to wind the line in the direction
indicated will cause the bump head to operate incorrectly.
3. Insert the ends of the line into the two holding
slots (Fig. 24).
Reinstalling The Reel
1. Insert the ends of the line through the eyelets in
the outer spool (Fig. 25), then grasp the ends and pull firmly to release the line from the holding slots in the spool.
2. Hold the inner reel in place and install the Bump Knob in the clockwise direction (see Fig. 18). Line installation is now complete.
3. Remove the inner reel (Fig. 19).
4. Use a clean cloth to clean the inner surface of the
outer spool (Fig. 20). Note: Always clean the inner reel, outer
spool, and shaft before reassembling the bump head.
5. Check the indexing teeth on the inner reel and
outer spool for wear (Fig. 21). If necessary, deburr or replace the reel and spool.
EN–9
Installing A Prewound Reel
1. Follow the instructions in THE CORRECT LINE TO USE.
2. Follow the instructions in REMOVING THE EXISTING REEL.
3. Follow the instructions in REINSTALLING THE REEL.
Air Filter Maintenance
Note: CLEAN AND RE-OIL THE AIR
FILTER EVERY 10 HOURS OF OPERATION. Your unit’s air filter is
one of the most important areas to maintain. If it is not maintained, you will void the warranty. Before cleaning, make sure the unit is turned off.
The condition of the air filter is important to the operation of the trimmer. A dirty air filter will restrict the air flow, which upsets the fuel-air mixture in the carburetor. The resulting symptoms are often mistaken for an out-of-adjustment carburetor. Therefore, check the condition of the air filter
before adjusting the carburetor. Refer to Air Filter Maintenance.
If the following conditions are experienced, it may be necessary to adjust the carburetor:
1. Remove the screws on each side of the
carburetor/air filter cover assembly. Remove the air filter cover (Fig. 11).
Note: The choke lever must be in the
“CHOKE” position to remove and install the air filter cover.
2. Remove the air filter (Fig. 26).
3. Wash the filter in detergent and water (Fig. 27).
Rinse the filter thoroughly and allow it to dry.
4. Apply enough clean SAE 30 oil to saturate the
filter (Fig. 28).
5. Squeeze the filter to spread the oil (Fig. 29).
6. Reinstall the filter (see Fig. 26), air filter cover
and screws (see Fig. 11).
Note: If the unit is operated without the
carburetor/air filter cover assembled, you will void the warranty.
Carburetor Adjustment
The engine will not idle
The engine hesitates or stalls on acceleration
The loss of engine power that is not corrected by
cleaning the air filter and muffler Note: Careless adjustments can seriously
damage your unit.
Adjusting the Carburetor
1. Clean the air filter if it is dirty. Refer to Air Filter Maintenance.
2. Make the initial settings with the engine stopped.
These initial settings should allow you to start and warm up the unit before making the final adjustments.
Initial Idle Speed Setting
A. For Walbro carburetors: Back the idle
speed screw (Fig. 30) out (counterclockwise) until it does not contact the carburetor throttle lever. Then turn the screw in (clockwise) until it just begins to move the throttle lever; then continue turning 2 full turns.
This unit is equipped with a diaphragm-type carburetor that has been carefully calibrated at the factory. In most cases, no further adjustment is required.
Note: To meet the 1995 California emission
regulations, the carburetor has adjustment needle limiter caps to restrict the amount of adjustment.
B. For Zama carburetors: Back the idle speed
screw (Fig. 31) out (counterclockwise) until it does not contact the throttle valve located inside of the carburetor. This is accomplished by carefully watching for the movement of the throttle lever to stop. Then turn the screw in (clockwise) until it just begins to move the throttle lever, then continue turning 1 1/2 turns.
EN–10
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