Dolmar MS-250.4, MS-251.4 User Manual

4 (1)

English / Français / Spanish C

Brush Cutter

String Trimmer

Débroussailleuse

Taille-bordures

Desbrozadora

Cortabordes

MS-250.4

MS-251.4

 

 

 

 

 

INSTRUCTION MANUAL

 

 

MANUEL D’INSTRUCTIONS

 

 

MANUAL DE INSTRUCCIONES

 

 

 

MS-250.4

MS-251.4

Important:

Read this instruction manual carefully before putting the Brush Cutter/String Trimmer into operation and strictly observe the safety regulations!

Preserve instruction manual carefully!

Recommandation importante:

Lire soigneusement ce manuel d’instructions avant de mettre la débroussailleuse / taille-bordures en service et observer rigoureusement les consignes de sécurité!

Conserver soigneusement ce manuel d’instructions.

Importante:

Leer cuidadosamente este manual de instrucciones antes de poner en marcha la máquina y observar estrictamente las normas de seguridad.

Conservar este manual de instrucciones con cuidado.

Thank you very much for purchasing the DOLMAR Brush Cutter/String trimmer. We are pleased to recommend to you the DOLMAR Brush Cutter/ String trimmer which is the result of a long development programme and many years of knowledge and experience.

Please read this booklet which refers in detail to the various points that will demonstrate its outstanding performance. This will assist you to obtain the best possible result from your DOLMAR Brush Cutter/String trimmer.

Table of Contents

Page

Symbols ......................................................................

1

Safety instructions .....................................................

2

Technical data ............................................................

6

Designation of parts ...................................................

7

Mounting of handle .....................................................

8

Mounting of protector .................................................

9

Mounting of cutter blade or nylon cutting head .........

10

Before start of operation ..........................................

11

Correct handling of machine .....................................

13

Points in operation and how to stop .........................

13

Resharpening the cutting tool ...................................

15

Servicing instructions ...............................................

17

Storage .....................................................................

20

SYMBOLS

You will note the following symbols when reading the instructions manual.

Read instruction Manual

Take Particular care and Attention

Forbidden

Keep distance

Flying object hazard

No Smoking

No open flame

Protective gloves must be worn

Kickback

Keep the area of operation clear of all persons and pets

I

O

Wear eye and ear protection (for String trimmer only)

Wear protective helmet, eye and ear protection (for Brush Cutter only)

Do not use metal blades (for String trimmer only)

Top permissible tool speed

Fuel (Gasoline)

Engine-Manual start

Emergency stop

First Aid

Recycling

ON/START

OFF/STOP

1

SAFETY INSTRUCTIONS

General Instructions

To ensure correct operation, user has to read this instruction manual to make himself familiar with the handling of the Brush Cutter/String trimmer. Users insufficiently informed will risk danger to themselves as well as others due to improper handling.

It is recommended only to lend the Brush Cutter/String trimmer to people who have proven to be experienced with Brush Cutter/String trimmers.

Always hand over the instruction manual.

First users should ask the dealer for basic instructions to familiarize oneself with the handling of an engine powered cutter.

Children and young persons aged under 18 years must not be allowed to operate the Brush Cutter/String trimmer. Persons over the age of 16 years may however use the device for the purpose of being trained only whilst under supervision of a qualified trainer.

Use Brush Cutter/String trimmers with the utmost care and attention.

Operate the Brush Cutter/String trimmer only if you are in good physical condition. Perform all work calmly and carefully. The user has to accept liability for others.

Never use the Brush Cutter/String trimmer after consumption of alcohol or drugs, or if feeling tired or ill.

Intended use of the machine

The Brush Cutter/String trimmer is only intended for cutter grass, weeds, Bushes, undergrowth it should not be used for any other purpose such as Edging or hedge cutting as this may cause injury.

Personal protective equipment

The clothing worn should be functional and appropriate, i.e. it should be tightfitting but not cause hindrance. Do not wear either jewelry or clothing which could become entangled with bushes or shrubs.

In order to avoid either head-, eye-, hand-or foot injuries as well as to protect your hearing the following protective equipment and protective clothing must be used during operation of the Brush Cutter/String trimmer.

Always wear a helmet where there is a risk of falling objects. The protective helmet (1) is to be checked at regular intervals for damage and is to be replaced at the latest after 5 years. Use only approved protective helmets.

The visor (2) of the helmet (or alternatively goggles) protects the face from flying debris and stones. During operation of the Brush Cutter/String trimmer always wear goggles, or a visor to prevent eye injuries.

Wear adequate noise protection equipment to avoid hearing impairment (ear muffs (3), ear plugs etc.).

The work overalls (4) protect against flying stones and debris. We strongly recommend that the user wears work overalls.

Special gloves (5) made of thick leather are part of the prescribed equipment and must always be worn during operation of the Brush Cutter/String trimmer.

When using the Brush Cutter/String trimmer, always wear sturdy shoes (6) with a non-slip sole. This protects against injuries and ensures a good footing.

Starting up the brush cutter

Please make sure that there are no children or other people within a working range of 15 meters (49ft), also pay attention to any animals in the working vicinity.

Before use always check that the Brush Cutter/String trimmer is safe for operation:

Check the security of the cutting tool, the control lever for easy action and check for proper functioning of the control lever lock.

Rotation of the cutting tool during idling speed is not allowed. Check with your dealer for adjustment if in doubt. Check for clean and dry handles and test the function of the start/stop switch.

Diagrammatic figure

15 Meter

2

Start the Brush Cutter/String trimmer only in accordance with the instructions. Do not use any other methods for starting the engine!

Use the Brush Cutter/String trimmer and the tools only for such applications as specified.

Only start the Brush Cutter/String trimmer engine, after the entire assembly is done. Operation of the device is only permitted after all the appropriate accessories are attached!

Before starting make sure that the cutting tool has no contact with hard objects such as branches, stones etc. as the cutting tool will revolve when starting.

The engine is to be switched off immediately in case of any engine problems.

Should the cutting tool hit stones or other hard objects, immediately switch off the engine and inspect the cutting tool.

Inspect the cutting tool at short regular intervals for damage (detection of hairline cracks by means of tapping-noise test).

Operate the Brush Cutter/String trimmer only with the shoulder strap attached which is to be suitably adjusted before putting the Brush Cutter/ String trimmer into operation. It is essential to adjust the shoulder strap according to the user’s size to prevent fatigue occurring during use. Never hold the cutter with one hand during use.

During operation always hold the Brush Cutter/String trimmer with both hands.

Always ensure a safe footing.

Operate the Brush Cutter/String trimmer in such a manner as to avoid inhalation of the exhaust gases. Never run the engine in enclosed rooms (risk of gas poisoning). Carbon monoxide is an odorless gas.

Switch off the engine when resting and when leaving the Brush Cutter/ String trimmer unattended, and place it in a safe location to prevent danger to others or damage to the machine.

Never put the hot Brush Cutter/String trimmer onto dry grass or onto any combustible materials.

The cutting tool has to be equipped with it’s appropriate guard. Never run the cutter without this guard!

All protective installations and guards supplied with the machine must be used during operation.

Never operate the engine with faulty exhaust muffler.

Shut off the engine during transport.

During transport over long distances the tool protection included with the equipment must always be used.

Ensure safe position of the Brush Cutter/String trimmer during car transportation to avoid fuel leakage.

When transporting the Brush Cutter/String trimmer, ensure that the fuel tank is completely empty.

When unloading the Brush Cutter/String trimmer from the truck, never drop the Engine to the ground or this may severely damage the fuel tank.

Except in case of emergency, never drop or cast the Brush Cutter/String trimmer to the ground or this may severely damage the Brush Cutter/String trimmer.

Remember to lift the entire equipment from the ground when moving the equipment. Dragging the fuel tank is highly dangerous and will cause damage and leakage of fuel, possibly causing fire.

Refuelling

Shut off the engine during refuelling, keep away from open flames and do not smoke.

Avoid skin contact with mineral oil products. Do not inhale fuel vapor. Always wear protective gloves during refuelling. Change and clean protective clothing at regular intervals.

Take care not to spill either fuel or oil in order to prevent soil contamination (environmental protection). Clean the Brush Cutter/String trimmer immediately after fuel has been spilt.

Avoid any fuel contact with your clothing. Change your clothing instantly if fuel has been spilt on it (to prevent clothing catching fire).

Inspect the fuel cap at regular intervals making sure that it can be securely fastened and does not leak.

Carefully tighten the fuel tank cap. Change location to start the engine (at least 3 meters away from the place of refuelling).

Never refuel in closed rooms. Fuel vapors accumulate at ground lever (risk of explosions).

Only transport and store fuel in approved containers. Make sure the fuel stored is not accessible to children.

Resting

Transport

Refuelling

Maintenance

Tool Replacement

 

 

 

 

 

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3

m

 

 

 

 

 

 

 

3

Method of operation

Only use the Brush cutter/String trimmer in good light and visibility. During the winter season beware of slippery or wet areas, ice and snow (risk of slipping). Always ensure a safe footing.

Never cut above waist height.

Never stand on a ladder and run the Brush cutter/String trimmer.

Never climb up into trees to perform cutting operation with the Brush cutter/ String trimmer.

Never work on unstable surfaces.

Remove sand, stones, nails etc. found within the working range. Foreign particles may damage the cutting tool and can cause dangerous kick-backs.

Before commencing cutting, the cutting tool must have reached full working speed.

Kickback

When operating the brush cutter, uncontrolled kickback may occur.

This is particularly the case when attempting to cut within a blade segment between 12 and 2 o’clock.

Never apply the brush cutter within a segment between 12 and 2 o’clock.

Never apply this segment of the brush cutter blade to solids, such as bushes and trees, etc., having a diameter in excess of 3 cm or the brush cutter will be deflected at great force with the risk of injuries.

Kickback prevention

To avoid kickbacks, observe the following:

Operation within a blade segment between 12 and 2 o’clock presents positive hazards, especially when using metal cutting tools.

Cutting operations within a blade segment between 11 and 12 o’clock, and between 2 and 5 o’clock, must only be performed by trained and experienced operators, and then only at their own risk.

Easy cutting with almost no kickback is possible within a blade segment between 8 and 11 o’clock.

Cutting Tools

Employ only the correct cutting tool for the job in hand.

MS-250.4, MS-251.4 with cutter blade (Star Blade (4 teeth), Eddy Blade (8 teeth)), Nylon cutting head

For cutting thick materials, such as weed, high grass, bushes, shrubs, underwood, thicket etc. (max. 2 cm dia. thickness). Perform this cutting work by swinging the brush cutter evenly in half-circles from right to left (similar to using a scythe).

Maintenance instructions

The condition of the cutter, in particular of the cutting tool of the protective devices and also of the shoulder strap must be checked before commencing work. Particular attention is to be paid to the cutting blades which must be correctly sharpened.

Turn off the engine and remove spark plug connector when replacing or sharpening cutting tools, and also when cleaning the cutter or cutting tool.

Caution:

Kickback

Diagrammatic flgure

Diagrammatic flgure

4

Never straighten or weld damaged cutting tools.

Operate the Brush cutter/Grass trimmer with as little noise and contamination as possible. In particular check the correct setting of the carburetor.

Clean the Brush cutter/Grass trimmer at regular intervals and check that all screws and nuts are well tightened.

Never service or store the Brush cutter/Grass trimmer in the vicinity of naked flames.

Always store the Brush cutter/Grass trimmer in locked rooms and with an emptied fuel tank.

Observe the relevant accident prevention instructions issued by the relevant trade associations and by the insurance companies. Do not perform any modifications on the Brush cutter/Grass trimmer as this will endanger your safety.

The performance of maintenance or repair work by the user is limited to those activities as described in the instruction manual. All other work is to be done by an Authorized Service Agent. Use only genuine spare parts and accessories released and supplied by DOLMAR. Use of non-approved accessories and tools means increased risk of accidents.

DOLMAR will not accept any liability for accidents or damage caused by the use of non-approved cutting tools and fixing devices of cutting tools, or accessories.

First Aid

In case of accident make sure that a first-aid box is available in the vicinity of the cutting operations. Immediately replace any item taken from the first aid box.

When asking for help, please give the following information:

Place of accident

What happened

Number of injured persons

Kind of injuries

Your name

Packaging

The DOLMAR Brush cutter/Grass trimmer will be delivered in two protective cardboard boxes to prevent transport damage. Cardboard is a basic raw material and is therefore consequently reusable or suitable for recycling (waste paper recycling).

5

TECHNICAL DATA MS-250.4, MS-251.4

 

 

MS-251.4

 

 

MS-250.4

Model

 

 

 

 

 

 

Loop handle

 

 

U handle

 

 

 

 

 

 

 

 

 

Dimensions : length x width x height (without cutting blade)

mm

1760x330x265

 

1760x600x405

 

 

 

 

 

 

Mass (without plastic guard and cutting blade)

kg

5.2

 

 

5.4

 

 

 

 

 

 

Volume (fuel tank)

L

 

 

0.5

 

 

 

 

 

Volume (oil tank)

L

 

 

0.08

 

 

 

 

 

Engine displacement

cc

 

 

24.5

 

 

 

 

 

Maximum engine performance

HP

 

 

0.885 at 7000 /min

 

 

 

 

 

Engine speed at recommended max. spindle speed

/min

 

 

8500

 

 

 

 

 

Maximum spindle speed (corresponding)

/min

 

 

6500

 

 

 

 

 

Maximum fuel consumption

kg/h

 

 

0.33

 

 

 

 

 

Maximum specific fuel consumption

g/HPh

 

 

304

 

 

 

 

 

Idling speed

/min

 

 

3000

 

 

 

 

 

Clutch engagement speed

/min

 

 

3750

 

 

 

 

 

Carburetor

type

 

 

WALBRO WYL

 

 

 

 

 

Ignition system

type

 

 

Solid state ignition

 

 

 

 

 

Spark plug

type

 

 

NGK CMR6A

 

 

 

 

 

Electrode gap

mm

 

 

0.7 - 0.8

 

 

 

 

Fuel

 

 

Automobile gasoline

 

 

 

Engine Oil

 

SAE 10W-30 oil of API Ciassification,

 

Class SF or higher (4-stroke engine for automobile)

 

 

 

 

 

 

 

Gear ratio

 

 

 

14/19

 

 

 

 

 

 

6

DESIGNATION OF PARTS

MS-250.4

Brush Cutter

MS-251.4

String trimmer

21

 

 

 

 

 

 

 

 

GB

DESIGNATION OF PARTS

 

 

 

 

 

 

 

 

 

 

1

Fuel Tank

 

 

 

 

2

Rewind Starter

 

 

 

 

3

Air Cleaner

 

 

 

 

4

I-O Switch (on/off)

 

 

 

 

5

Spark Plug

 

 

 

 

6

Exhaust Muffler

 

 

 

 

7

Clutch Case

 

 

8

Rear Grip

 

9

Hanger

 

 

 

 

 

 

 

 

10

Handle

 

 

 

 

11

Control Lever

 

 

24

12

Control Cable

 

 

13

Shaft

 

 

 

 

 

14

Protector

 

 

 

25

15

Gear Case/Head Case

 

 

 

16

Handle Holder

 

 

 

 

 

 

 

 

17

Cutter Blade

 

 

 

 

18

Nylon Cutting Head

 

 

20

Fuel Filler Cap

 

21

Starter Knob

 

 

 

 

 

 

 

 

24

Exhaust Pipe

 

 

 

 

25

Oil Gauge

 

 

 

 

 

 

7

MOUNTING OF HANDLE

CAUTION: Before doing any work on the brush cutter, always stop the engine and pull the spark plug connector off the spark plug.

Always wear protective gloves!

CAUTION: Start the brush cutter only after having assembled it completely.

For machines with U Handle models

Insert the handle bar into the handle holder, making sure that the boss in the handle holder fits into the hole in the handle.

After the handle bar is in place, tighten the four bolts (M5 x 25).

NOTE: Be sue the bolts are tight, but do not overtighten.

Fit the control cable (together with the earth cord) to the handle with two clips

(3).

Avoid any tendency of the control cable to loop at the handle bar.

For machines with Loop Handle

Fix a barrier to the left side of the machine together with the handle for operator’s protection.

Do not adjust position of the loop handle too close to the control grip. Keep not less than 250mm distance between the handle and the grip.

(a distance collar is provided for this purpose.)

 

 

e

 

 

in

 

 

g

 

n

to

e

 

 

 

(3)

to engine

8

MOUNTING OF PROTECTOR

To meet the applicable safety provisions, only the tool/ protector combinations as indicated in the table must be used.

Be sure to use genuine DOLMAR cutter blades or nylon cutting head.

The cutter blade must be well polished, free of cracks or breakage. If the cutter blade hits against a stone during operation, stop the engine and check the blade immediately.

Polish or replace the cutter blade every three hours of operation.

If the nylon cutting head hits against a stone during operation, stop the engine and check the nylon cutting head immediately.

CAUTION : The appropriate protector must always be installed, for your own safety and in order to comply with accident-prevention regulations.

Operation of the equipment without the guard being in place is not permitted.

For MS-250.4

 

MS-250.4

 

 

 

Protector for metal blades

Star Blade

Protector for metal blades (Use of protector for metal

 

blade/cord cutter)

 

MS-251.4

 

Protector for cord cutter

Nylon cutting head

Protector for cord cutter (Use of protector for metal

 

blade/cord cutter)

The outside diameter of the cutter blade must be 230mm (9-1/16"). Never use any blades surpassing 230mm (9-1/16") in outside diameter.

For MS-250.4, MS-251.4

Install the clamp (3) on the shaft so that the projection of the clamp (3) is inserted into the opening between the gear case (1) and the shaft. Secure the protector (4) with the installation bolts M6 x 30 (2) and screw M5 x 8 (5).

Use of protector for metal blade / cord cutter.

(2)

(3)

(1)

 

 

In use of the metal blade, fasten the protector (4) to the clamp (3) with two bolts M6 x 30 (2).

NOTE : Tighten the right and left bolts evenly so that the gap between the clamp (3) and the protector (4) will be constant.

Otherwise, the protector sometimes may not function as specified.

(4)

– In use of the cord cutter, insert the protector (2) into the protector (1), and

(1)

(3)

fasten them with two screw (4) and two nuts (3).

 

 

(2)

(4)

9

MOUNTING OF CUTTER BLADE OR NYLON CUTTER HEAD

Turn the machine upside down, and you can replace the cutter blade easily.

For MS-250.4, MS-251.4

Insert the hex wrench through the hole in the gear case and rotate the receiver washer (3) until it is locked with the hex wrench.

Loosen the nut (1) (left-hand thread) with the socket wrench and remove the nut (1), and clamp washer (2).

For MS-250.4 with the hex wrench still in place.

Mount the cutter blade onto the shaft so that the guide of the receiver washer

(3)fits in the arbor hole in the cutter blade. Install the clamp washer (2) and secure the cutter blade with the nut (1).

[Tightening torque: 13 - 23 N-m]

NOTE: Always wear gloves when handling the cutter blade.

NOTE: The cutter blade-fastening nut (with spring washer) is a consumable

part. If there appears any wear or deformation on the spring washer, Hex wrench replace the nut.

Mounting of nylon cutting head

For MS-251.4

To install the nylon cutting head (7), remove the tightening nut (8).

Insert the socket-head wrench (11) through the hole in the gear case and tum the support washer until it will be locked with its notch (12) (or the shaft will be locked).

Then screw the nylon cutting head onto the shaft by turning it counterclockwise.

Remove the socket-head wrench.

Make sure that the blade is the left way up.

Rotation

10

BEFORE START OF OPERATION

Inspection and Refill of Engine Oil

Perform the following procedure, with the engine cooled down.

While keeping the engine level, remove the oil gauge, and confirm that the oil is filled within the upper and lower limit marks.

When the oil is in short in such a way that the oil gauge touches the oil only by its tip, in particular with the oil gauge remaining inserted in the crankcase without screwing-in (Fig. 1), refill new oil near the port (Fig. 2).

For reference, the oil refill time is about 10h (10 times or 10 tanks of oil refill).

If the oil changes in color or mixes with dirt, replace it with new one. (For the interval and method of replacement, refer to P 17)

Recommended oil: SAE 10W-30 oil of API Classification, Class SF or higher (4-stroke engine for automobile)

Oil volume:

Approx. 0.08L

Note: If the engine is not kept upright, oil may go into around the engine, and may be refilled excessively.

If the oil is filled above the limit, the oil may be contaminated or may catch fire with white.

Point 1 in Replacement of Oil “Oil Gauge”

Remove dust or dirt near the oil refill port, and detach the oil gauge.

Keep the detached oil gauge free of sand or dust. Otherwise, any sand or dust adhering to the oil gauge may cause irregular oil circulation or wear on the engine parts, which will result in troubles.

As an example to keep the oil gauge clean, it is recommended to insert the oil gauge on its knob side into the engine cover, as shown in Fig.3.

Upper limit

(Edge of oil refill port)

If oil adheres around this tip, refill new oil.

Fig.1

Fig.2

Oil gauge

Fig.3

11

(1) Keep the engine level, and detach the oil gauge.

(2)Fill oil up to the edge of the oil refill port. (Refer to Fig.2 of the preceding page).

Feed oil with the lubricant refill container.

(3)Securely tighten the oil gauge. Insufficient tightening may cause oil leakage.

Point 2 in Replacement of Oil: “If oil spills out”

If oil spills out between the fuel tank and engine main unit, the oil is sucked into through the cooling air intake port, which will contaminate the engine. Be sure to wipe out spilt oil before start of operation.

REFUELING

Handling of Fuel

It is necessary to handle fuel with utmost care. Fuel may contain substances similar to solvents. Refueling must be performed in a sufficiently ventilated room or in the open air. Never inhale fuel vapor, and keep fuel away from you. If you touch fuel repeatedly or for a long time, the skin becomes dry, which may cause skin disease or allergy. If fuel enters into the eye, clean the eye with fresh water. If your eye remains still irritated, consult your doctor.

Storage Period of Fuel

Fuel should be used up within a period of 4 weeks, even if it is kept in a special container in a well-ventilated shade. If a special container is not used or if the container is not covered, fuel may deteriorate in one day.

STORAGEOFMACHINEAND REFILLTANK

Keep the machine and tank at a cool place free from direct sunshine.Never keep the fuel in the cabin or trunk.

Fuel

The engine is a four-stroke engine. Be sure to use an automobile gasoline (regular gasoline or premium gasoline).

Points for Fuel

Never use a gasoline mixture which contains engine oil. Otherwise, it will cause excessive carbon accumulation or mechanical troubles.

Use of deteriorated oil will cause irregular startup.

Refueling

WARNING: INFLAMMABLES STRICTLY PROHIBITED

Gasoline used: Automobile gasoline (unleaded gasoline)

Loosen the tank cap a little so that there will be no difference in atmospheric pressure.

Detach the tank cap, and refuel, discharging air by tilting the fuel tank so that the refuel port will be oriented upward. (Never refill fuel full to the oil refill port.)

Wipe well the periphery of the tank cap to prevent foreign matter from entering into the fuel tank.

After refueling, securely tighten the tank cap.

If there is any flaw or damage on the tank cap, replace it.

The tank cap is consumable, and therefore should be renewed every two to three years.

Fuel tank cap

Fuel upper limit

Fuel tank

12

CORRECT HANDLING OF MACHINE

Attachment of shoulder strap

Adjust the strap length so that the cutter blade will be kept parallel with the ground.

Detachment

For MS-251.4

In an emergency, push the notches (1) at both sides, and you can detach the machine from you.

Be extremely careful to maintain control of the machine at this time. Do not allow the machine to be deflected toward you or anyone in the work vicinity.

WARNING: Failure to maintain complete control of the machine at all could result in serious bodily injury or DEATH.

Hanger

For MS-250.4

In case of emergency, remove the emergency detachment lever (2) by pulling strongly with a finger. The machine sill detach from body.

Be extremely careful to maintain control of the machine at this time. Do not

allow the machine to be deflected toward you or

anyone in the work

vicinity.

(2)

WARNING: Failure to maintain complete control of the machine at all could result in serious bodily injury or DEATH.

Hanger

POINTS IN OPERATION AND HOW TO STOP

Observe the applicable accident prevention regulations!

STARTING

Move at least 3m away from the place of refuelling. Place the brush cutter on a clean piece of ground taking care that the cutting tool does not come into contact with the ground or any other objects.

A:Cold start

Throttle control dial

 

1) Set this machine on a flat space.

I-O switch (1)

Throttle lever (6)

OPERATION

Low speed

Lock-off lever

 

 

High speed

13

For machine with U Handle or Loop Handle

1)Set the I-O switch (1) to OPERATION.

2)Choke lever

Close the choke lever. Choke opening:

Full closing in cold or when the engine is cold.

Full or half opening in restart just after stop of operation.

3)Primer pump

Continue to push the primer pump until fuel enters into the primer pump. (In general, fuel enters into the primer pump by 7 to 10 pushes.)

If the primer pump is pushed excessively, an excess of gasoline returns to the fuel tank.

4)Recoil starter

Pull the start knob gently until it is hard to pull (compression point). Then, return the start knob, and pull it strongly.

Never pull the rope to the full. Once the start knob is pulled, never release your hand immediately. Hold the start knob until it returns to its original point.

5)Choke lever

When the engine starts, open the choke lever.

Open the choke lever progressively while checking the engine operation. Be sure to open the choke lever to the full in the end.

In cold or when the engine is cooled down, never open the choke lever suddenly. Otherwise, the engine may stop.

6)Warm-up operation

Continue warm-up operation for 2 to 3 minutes.

CLOSE

Carburetor

Primer Pump

OPEN

Note: – If the starter handle is pulled repeatedly when the choke lever remains at “START” position, the engine will not start easily due to excessive fuel intake.

In case of excessive fuel intake, remove the spark plug and pull the starter handle slowly to remove excess fuel. Also, dry the electrode section of the spark plug.

Caution during operation:

If the throttle lever is opened fully in a no-load operation, the engine rotation is increased to 10,000/min or more. Never operate the engine at a higher speed than required and at an approximate speed of 6,000 - 8,500/min.

14

B: Startup after warm-up operation

1)Push the primer pump repeatedly.

2)Keep the throttle lever at the idling position.

3)Pull the recoil starter strongly.

4)If it is difficult to start the engine, open the throttle by about 1/3. Pay attention to the cutter blade which may rotate.

Attention in Operation

When the engine is operated upside down, white smoke may come out from the muffler.

STOPPING

STOP

1)Release the throttle lever (6) fully, and when the engine rpm has lowered, set the I-O switch to STOP the engine will now stop.

2)Be aware that the cutting head may not stop immediately and allow it to slow down fully.

I-O switch (1)

Throttle lever (6)

ADJUSTMENT OF LOW-SPEED ROTATION (IDLING)

When it is necessary to adjust the low-speed rotation (idling), perform it by the carburetor adjusting screw.

CHECKUPOF LOW-SPEEDROTATION

Set the low-speed rotation to 3000/min.

If it is necessary to change the rotation speed, regulate the adjusting screw (illustrated on the left), with Phillips screwdriver.

Turn the adjusting screw to the right, and the engine rotation will increase. Turn the adjusting screw to the left, and the engine rotation will drop.

The carburetor is generally adjusted before shipment. If it is necessary to readjust it, please contact Authorized Service Agent.

Adjusting screw

Carburetor

RESHARPENING THE CUTTING TOOL

CAUTION : The cutting tools mentioned below must only be resharpened by an authorized facility. Manual resharpening will result in imbalances of the cutting tool causing vibrations and damage to the equipment.

cutter blade (star blade (4 teeth), eddy blade (8 teeth))

An expert resharpening and balancing service is provided by Authorized Service Agents.

NOTE : To increase the service life of the cutter blade (star blade, eddy blade) it may be turned over once, until both cutting edges have become blunt.

15

NYLON CUTTING HEAD

The nylon cutting head is a dual string trimmer head capable of both automatic and bump & feed mechanisms.

The nylon cutting head will automatically feed out the proper length of nylon cord by the changes in centrifugal force caused by increasing or decreasing rpms. However, to cut soft grass more efficiently, bump the nylon cutting head against the ground to feed out extra cord as indicated under operation section.

Operation

Increase the nylon cutting head speed to approx. 6,000/min.

Low speed (under 4,800/min) is not suitable, the nylon cord will not feed out properly at low speed.

The most effective cutting area is shown by the shaded area.

If the nylon cord does not feed out automatically proceed as follows:

1.Release the throttle lever to run the engine idle and then squeeze the throttle lever fully. Repeat this procedure until the nylon cord feeds out to the proper length.

2.If the nylon cord is too short to feed out automatically with the above procedure, bump the knob of the nylon cutting head against the ground to feed out the nylon cord.

3.If the nylon cord does not feed out with procedure 2, rewind/replace the nylon cord by following the procedures described under “Replacing the nylon cord”.

Replacing the nylon cord

First, stop the engine.

Press on the housing latches inward to lift off the cover, then remove the spool.

Hook the center of new nylon cord into the notch in the center of the spool, with one end of the cord extending about 80mm (3-1/8") more than the other. Then wind both ends firmly around the spool in the direction of the head rotation (left-hand direction indicated by LH and right-hand direction by RH on the side of the spool).

Wind all but about 100mm (3-15/16") of the cords, leaving the ends temporarily hooked through a notch on the side of the spool.

Mount the spool in the housing so that the grooves and protrusions on the spool match up with those in the housing. Keep the side with letters on the spool visible on the top. Now, unhook the ends of the cord from their temporary position and feed the cords through the eyelets to come out of the housing.

Most effective cutting area

Idle speed

Full speed

Knob

 

Cover

 

Latches

Press

Press

 

Spool

80mm(3-1/8”)

 

For left hand rotation

Spool

100mm(3-15/16”)

Notches

Eyelets

16

Align the protrusion on the underside of the cover with the slots of the eyelets.

Then push cover firmly onto the housing to secure it.

Cover

Protrusion

Slot of eyelet

SERVICING INSTRUCTIONS

CAUTION : Before doing any work on the Brush cutter/String trimmer, always stop the engine and pull the plug cap off the spark plug (see “checking the spark plug”).

Always wear protective gloves!

To ensure a long service life and to avoid any damage to the equipment, the following servicing operations should be performed at regular intervals.

Daily checkup and maintenance

Before operation, check the machine for loose screws or missing parts. Pay particular attention to the tightness of the cutter blade or nylon cutting head.

Before operation, always check for clogging of the cooling air passage and the cylinder fins. Clean them if necessary.

Perform the following work daily after use:

Clean the Brush cutter/String trimmer externally and inspect for damage.

Clean the air filter. When working under extremely dusty conditions, clean the filter the severall times a day.

Check the blade or the nylon cutting head for damage and make sure it is firmly mounted.

Check that there is sufficient difference between idling and engagement speed to ensure that the cutting tool is at a standstill while the engine is idling (if necessary reduce idling speed).

If under idling conditions the tool should still continue to run, consult your nearest Authorized Service Agent.

Check the functioning of the I-O switch, the lock-off lever, the control lever, and the look button.

REPLACEMENT OF ENGINE OIL

Deteriorated engine oil will shorten the life of the sliding and rotating parts to a great extent. Be sure to check the period and quantity of replacement.

ATTENTION : In general, the engine main unit and engine oil still remain hot just after the engine is stopped. In replacement of oil, confirm that the engine main unit and engine oil are sufficiently cooled down. Otherwise, there may remain a risk of scald.

Note: If the oil filled above the limit, it may be contaminated or may catch fire with white smoke.

Interval of replacement : Initially, every 20 operating hours, and subsequently every 50 operating hours Recommended oil : SAE10W-30 oil of API Classification SF Class or higher (4-stroke engine oil for automobile)

In replacement, perform the following procedure.

Fuel tank cap

1)Confirm that the tank cap is tightened securely.

2)Detach the oil gauge.

Keep the oil gauge free from dust or dirt.

Oil gauge

17

3) Place waste or paper near the oil refill port.

Waste or paper

4)Detach the oil gauge, and drain oil, tilting the main unit toward the oil refill port.

Drain oil in a container.

5)Keep the engine level, and feed new oil up to the edge of the oil refill port. In refill, use a lubricant refill container.

6)After refill, securely tighten the oil gauge. Insufficient tightening of the oil gauge will lead to oil leakage.

POINTS ON OIL

Never discard replaced engine oil in garbage, earth or sewage ditch. Disposal of oil is regulated by law. In disposal, always follow the relevant laws and regulations. For any points remaining unknown, contact Authorized Service Agent.

Oil will deteriorate even when it is kept unused. Perform inspection and replacement at regular intervals (replace with new oil every 6 months).

CLEANING OF AIR CLEANER

DANGER:INFLAMMABLESSTRICTLYPROHIBITED

Interval of Cleaning and Inspection: Daily (every 10 operating hours)

Turn the choke lever to the full close side, and keep the carburetor off from dust or dirt.

Remove the air cleaner cover-fixing bolts.

Pull the cover lower side and detach the air cleaner cover.

If oil adheres to the element (sponge), squeeze it firmly.

For heavy contamination:

1)Remove the element (sponge), immerse it in warm water or in water-diluted neutral detergent, and dry it completely.

2)Clean the element (felt) with gasoline, and dry it completely.

Before attaching the element, be sure to dry it completely. Insufficient drying of the element may lead to difficult startup.

Wipe out with waste cloth, oil adhering around the air cleaner cover and plate breather.

Immediately after cleaning is finished, attach the cleaner cover and tighten it with fixing bolts. (In remounting, first place the upper claw, and then the lower claw.)

Points in Handling Air Cleaner Element

Clean the element several times a day, if excessive dust adheres to it.

If operation continues with the element remaining not cleared of oil, oil in the air cleaner may fall outside, resulting in oil contamination.

Plate

Element (sponge)

Air cleaner cover

Breather Part

Element (felt)

Fixing bolt

Pick this part and remove the element (felt).

18

CHECKING THE SPARK PLUG

Only use the supplied universal wrench to remove or to install the spark plug.

The gap between the two electrodes of the spark plug should be 0.7-0.8mm (0.028”-0.032”). If the gap is too wide or too narrow, adjust it. If the spark plug is clogged with carton or fouled, clean it thoroubhly or replace it.

CAUTION : Never touch the spark plug connector while the engine is running (danger of high voltage electric shock).

SUPPLY OF GREASE TO GEAR CASE

Supply grease (Shell Alvania 2 or equivalent) to the gear case through the grease hole every 30 hours. (Genuine DOLMAR grease may be purchased from your DOLMAR dealer.)

CLEANING OF FUEL FILTER

WARNING: INFLAMMABLES STRICTLY PROHIBITED

Interval of Cleaning and Inspection: Monthly (every 50 operating hours)

Suction head in the fuel tank

The fuel filler (1) of the suction head is used to filler the fuel required by the carburetor.

A periodical visual inspection of the fuel filter is to be conducted. For that purpose open the tank cap, use a wire hook and pull out the suction head through the tank opening. Filters found to have hardened, been polluted or clogged up are to be replaced.

Insufficient fuel supply can result in the admissible maximum speed being exceeded. It is therefore important to replace the fuel filter at least quarterly to ensure satisfactory fuel supply to the carburetor.

REPLACEMENT OF FUEL PIPE

CAUTION: INFLAMMABLES STRICTLY PROHIBITED

Interval of Cleaning and Inspection: Daily (every 10 operating hours) Replacement: Annually (every 200 operating hours)

Replace the fuel pipe every year, regardless of operating frequency. Fuel leakage may lead to fire.

If any leakage is detected during inspection, replace the oil pipe immediately.

0.7mm-0.8mm (0.028”-0.032”)

Gear case

Grease hole

Fuel pipe

House clamp

Fuel

filter(1)

Fuel pipe

INSPECTION OF BOLTS, NUTS AND SCREWS

Retighten loose bolts, nuts, etc.

Check for fuel and oil leakage.

Replace damaged parts with new ones for safety operation.

CLEANING OF PARTS

Keep the engine always clean.

Keep the cylinder fins free of dust or dirt. Dust or dirt adhering to the fins will cause seizure.

REPLACEMENT OF GASKETS AND PACKINGS

In reassembling after the engine is dismounted, be sure to replace the gaskets and packings with new ones.

Any maintenance of adjustment work that is not included and described in this manual is only to be performed by Authorized Service Agents.

19

STORAGE

WARNING: When draining the fuel, be sure to stop the engine and confirm that the engine cools down.

Just after stopping the engine, it may still hot with possibility of burns, inflammability and fire.

ATTENTION: When the machine is kept out of operation for a long time, drain up all fuel from the fuel tank and carburetor, and keep it at a dry and clean place.

Drain up fuel from the fuel tank and carburetor according to the following procedure:

1)Remove the fuel tank cap, and drain fuel completely.

If there is any foreign matter remaining in the fuel tank, remove it completely.

2)Pull out the fuel filter from the refill port using a wire.

3) Push the primer pump until fuel is drained from there, and drain fuel

Drain fuel

Humidity

coming into the fuel tank.

 

 

 

4)Reset the filter to the fuel tank, and securely tighten the fuel tank cap.

5)Then, continue to operate the engine until it stops.

Remove the spark plug, and drip several drops of engine oil through the spark plug hole.

Gently pull the starter handle so that engine oil will spread over the engine, and attach the spark plug.

Attach the cover to the cutter blade.

During storage, keep the rod horizontal or keep the machine upright with the blade edge oriented upward. (In this case, pay full attention to prevent the machine from falling.)

Never store the machine with the cutter blade edge oriented downward. Lubricating oil may spill out.

Keep the drained fuel in a special container in a well-ventilated shade.

Attention after long-time storage

Before startup after long-time shutdown, be sure to replace oil (refer to P 17). Oil will deteriorate while the machine is kept out of operation.

Fault location

Fault

System

Observation

Cause

 

 

 

 

Engine not starting or with

Ignition system

Ignition spark O.K.

Fault in fuel supply or compression system, mechanical

difficulty

 

 

defect

 

 

No ignition spark

STOP-switch operated, wiring fault or short circuit, spark

 

 

 

plug or connector defective, ignition module faulty

 

Fuel supply

Fuel tank filled

Incorrect choke position, carburetor defective, fuel supply

 

 

 

line bent or blocked, fuel dirty.

 

Compression

No compression when

Cylinder bottom gasket defective, crankshaft seals

 

 

pulled over

damaged, cylinder or piston rings defective or improper

 

 

 

sealing of spark plug

 

Mechanical fault

Starter not engaging

Broken starter spring, broken parts inside of the engine

Warm start problems

 

Tank filled ignition spark

Carburetor contaminated, have it cleaned

 

 

existing

 

Engine starts but dies

Fuel supply

Tank filled

Incorrect idling adjustment, carburetor contaminated

 

 

 

Fuel tank vent defective, fuel supply line interrupted,

 

 

 

cable or STOP-switch faulty

Insufficient performance

Several systems

Engine idling poor

Air filter contaminated, carburetor contaminated, muffler

 

may simultaneously

 

clogged, exhaust duct in the cylinder clogged

 

be affected

 

 

 

 

 

 

20

Dolmar MS-250.4, MS-251.4 User Manual

Operating time

 

Before

After

Daily

 

 

 

 

Shutdown

Corres-po

 

 

30h

50h

200h

 

 

operation

lubrication

(10h)

/rest

nding P

Item

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Inspect/clean

 

 

 

 

 

 

 

11

Engine oil

 

 

 

 

 

 

 

 

 

 

 

Replace

 

 

 

 

*1

 

 

 

17

Tightening parts

Inspect

 

 

 

 

 

 

 

19

(bolt, nut)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Clean/inspect

 

 

 

 

 

 

 

Fuel tank

 

 

 

 

 

 

 

 

 

 

 

Drain fuel

 

 

 

 

 

 

 

*3

20

Throttle lever

Check function

 

 

 

 

 

 

 

13

Stop switch

Check function

 

 

 

 

 

 

 

13

Cutting blade

Inspect

 

 

 

 

 

 

9

Low-speed rotation

Inspect/adjust

 

 

 

 

 

 

 

15

Air cleaner

Clean

 

 

 

 

 

 

 

18

Ignition plug

Inspect

 

 

 

 

 

 

 

19

Cooling air duct

Clean/inspect

 

 

 

 

 

 

 

19

 

Inspect

 

 

 

 

 

 

 

19

Fuel pipe

 

 

 

 

 

 

 

 

 

 

 

Replace

 

 

 

 

 

*2

 

Gear-case grease

Refill

 

 

 

 

 

 

 

19

Fuel filter

Clean/replace

 

 

 

 

 

 

 

19

Clearance between air intake

Adjust

 

 

 

 

 

 

*2

 

 

 

 

 

 

 

 

valve and air discharge valve

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Engine overhaul

 

 

 

 

 

 

*2

 

Carburetor

Drain fuel

 

 

 

 

 

 

 

*3

20

*1 Perform initial replacement after 20h operation.

*2 For the 200 operating hour inspection, request Authorized Service Agent or a machine shop. *3 After emptying the fuel tank, continue to run the engine and drain fuel in the carburetor.

21

TROUBLESHOOTING

Before making a request for repairs, check a trouble for yourself. If any abnormality is found, control your machine according to the description of this manual. Never tamper or dismount any part contrary to the description. For repairs, contact Authorized Service Agent or local dealership.

 

State of abnormality

Probable cause (malfunction)

Remedy

 

 

 

 

Failure to operate primer pump

Push 7 to 10 times.

 

 

 

 

 

 

 

 

 

 

Low pulling speed of starter rope

Pull strongly.

 

 

 

 

 

 

 

 

 

 

Lack of fuel

Feed fuel.

 

 

 

 

 

 

 

 

 

 

Clogged fuel filter

Clean

 

 

 

 

 

 

 

 

 

 

Broken fuel tube

Straighten fuel tube

 

 

 

 

 

 

 

 

 

 

Deteriorated fuel

Deteriorated fuel makes starting more difficult.

 

 

 

 

 

Replace with new one. (Recommended

 

 

 

 

 

replacement: 1 month)

 

 

 

 

 

 

 

 

 

 

Excessive suction of fuel

Set throttle lever from medium speed to high

 

 

 

 

 

speed, and pull starter handle until engine

 

 

 

 

 

starts. Once engine starts, cutter blade

Engine does not start

 

starts rotating. Pay full attention to cutter

 

blade.

 

 

 

 

 

 

 

 

 

 

If engine will not start still, remove spark plug,

 

 

 

 

 

make electrode dry, and reassemble them as

 

 

 

 

 

they originally are. Then, start as specified.

 

 

 

 

 

 

 

 

 

 

Detached plug cap

Attach securely

 

 

 

 

 

 

 

 

 

 

Contaminated spark plug

Clean

 

 

 

 

 

 

 

 

 

 

Abnormal clearance of spark plug

Adjust clearance

 

 

 

 

 

 

 

 

 

 

Other abnormality of spark plug

Replace

 

 

 

 

 

 

 

 

 

 

Abnormal carburetor

Make request for inspection and maintenance.

 

 

 

 

 

 

 

 

 

 

Starter rope cannot be pulled

Make request for inspection and maintenance

 

 

 

 

 

 

 

 

 

 

Abnormal drive system

Make request for inspection and maintenance

 

 

 

 

 

 

 

 

 

 

Insufficient warm-up

Perform warm-up operation

 

 

 

 

 

 

 

 

 

 

Choke lever is set to “CLOSE” although engine

Set to “OPEN”

 

 

 

 

is warmed up

 

 

 

 

 

Engine stops soon

 

 

Clogged fuel filter

Clean

Engine speed does not increase

 

 

Contaminated or clogged air cleaner

Clean

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Abnormal carburetor

Make request for inspection and maintenance

 

 

 

 

 

 

 

 

 

 

Abnormal drive system

Make request for inspection and maintenance

 

 

 

 

 

 

Cutter blade does not rotate

Loosened cutter blade-tightening nut

Tighten securely

 

 

 

 

 

 

 

 

 

 

Twigs caught by cutter blade or

Remove foreign matter

 

 

 

 

dispersion-preventing cover

 

 

 

 

 

 

Stop engine immediately

 

Abnormal drive system

Make request for inspection and maintenance.

 

 

 

 

 

 

 

 

 

 

 

 

Main unit vibrates abnormally.

Broken, bent or worn cutter blade

Replace cutter blade

 

 

 

 

 

 

 

 

 

 

Loosened cutter blade-tightening nut

Tighten securely

 

 

 

 

 

 

 

 

 

 

Shifted convex part of cutter blade and cutter

Attach securely

 

 

 

 

blade support fitting

 

Stop engine immediately

 

 

 

 

 

 

Abnormal drive system

Make request for inspection and maintenance

 

 

 

 

 

 

 

 

 

 

Cutter blade does not stop immediately.

High idling rotation

Adjust

 

 

 

 

 

 

 

 

 

 

Detached throttle wire

Attach securely

 

Stop engine immediately

 

 

 

 

 

Abnormal drive system

Make request for inspection and maintenance

 

 

 

 

 

 

 

 

 

 

Engine does not stop.

Detached connector

Attach securely

 

 

 

 

 

 

 

 

 

 

Abnormal electric system

Make request for inspection and maintenance.

 

 

 

 

 

Run engine at idling, and set choke

 

 

 

 

lever to CLOSE.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

When the engine does not start after warm-up operation:

If there is no abnormality found for the check items, open the throttle by about 1/3 and start the engine.

22

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