BT25-00000 (404)
OWNER / OPERATOR MANUAL
LINE TRIMMER
BT250
WARNING
WARNING
The engine exhaust from this product
contains chemicals known to the State
of California to cause cancer, birth
defects or other reproductive harm.
Before using our products, please
read this manual carefully to
understand the proper use of your
unit.
APPLICABLE SERIAL NUMBERS :
DRIVE UNIT 40400101 and up
ENGINE UNIT KU40001 and up
SAFETY FIRST
Instructions contained in warnings within this
manual marked with a
symbol concern
critical points which must be taken into
consideration to prevent possible serious
bodily injury, and for this reason you are
requested to read all such instructions
carefully and follow them without fail.
■ WARNINGS IN THE MANUAL
WARNING
This mark indicates instructions which must be
followed in order to prevent accidents which could
lead to serious bodily injury or death.
IMPORTANT
This mark indicates instructions which must be
followed, or it leads to mechanical failure,
breakdown, or damage.
NOTE
This mark indicates hints or directions useful in the
use of the product.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
CONTENTS
Parts location …………………………………4
Specifications …………………………………4
Warning labels on the machine ……………5
Symbols on the machine ……………………6
For safe operation ……………………………7
Set up …………………………………………13
Fuel……………………………………………14
Operation ……………………………………16
Maintenance …………………………………19
Storage ………………………………………24
Troubleshooting guide ………………………24
Parts list ………………………………………25
1. Parts location
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Loop handle
Ignition switch
Throttle cable
Throttle lever
Drive shaft housing
Debris guard
Cutting line head
Gear case
Spark arrester
Starter knob
Fuel tank
Primer pump
Choke lever
Air cleaner cover
2. Specifications
■ BT250
Overall size(LxWxH)······················································ 63.0(1600)x13.0(330)x12.0(305) in(mm)
Dry weight w/o acc.····························································································· 11.1 lbs (5.05kg)
Engine Type······················································································ Air-cooled 2-stroke gasoline
Model······································································································ Zenoah GT25N2
Displacement ······················································································· 1.6cu-in (25.4cm3)
Max. output·························································································· 1.2Hp at 8500 rpm
Fuel ······················································································· Mixture(Gasoline 50 : Oil 1)
Carburetor ··················································································· Walbro Diaphragm type
Spark plug ································································································· NGK BPMR7A
Fuel tank capacity······························································································ 22.3 fl.oz (0.62 )
Transmission··········································································· Centrifugal clutch, Rigid driveshaft
Reduction ratio ····················································································································· 1.000
Cutting head rotating direction······························································ Clockwise(Operator view)
Durability period····················································································································50hrs.
Standard Accessories
3.5 in. 2-line Head ····································································································· 1 pc.
Specifications are subject to change without notice.
4 
3. Warning labels on the machine
(1) Read owner's manual before operating this machine.
(2) Wear head, eye and ear protection.
(3) Warning/Attention
(4) Keep all children, bystanders and helpers 15 meters away from the brushcutter
IMPORTANT
If warning label peel off or become soiled and impossible to read, you should contact the dealer
from which you purchased the product to order new labels and affix them in the required
location(s).
WARNING
Never modify your brushcutter.
We won't warrant the machine, if you use the remodeled brushcutter or you don't observe
the proper usage written in the manual.
5 
4. Symbols on the machine
For safe operation and maintenance,
symbols are carved in relief on the machine.
According to these indications, please be
careful not to make a mistake.
(a) The port to refuel the "MIX GASOLINE"
Position: FUEL TANK CAP
(b) The direction A to close the choke
The direction B to open the choke
Position: AIR CLEANER COVER
INFORMATION
INFORMA
TION IMPORTANTE
IMPOR ANTE CONCERNANT LE MOTEUR
MOTEUR
CE MOTEUR EST CONFORME A LA REGLEMENTATION U.S. EPA 2005 POUR LES PETITS
MOTEURS HORS-ROUTE. DUREE DE CONFORMITE DES EMISSIONS : CATEGORIE A.
SE REFERER AU MODE D’EMPLOI POUR DE PLUS AMPLES INFORMATIONS.
FAMMILLE
AMMILLE DE MOTEUR
MOTEUR : 5HCPS.025AD;EM
CYLINDREE : 25cm3 DATE
TE DE FABRICA
FABRICATION
TION :
6 
5. For safe operation
1. Read this manual carefully until you
completely understand and follow all safety
and operating instructions.
2. Keep this manual handy so that you may refer
to it later whenever any questions arise. Also
note, if you have any questions which cannot
be answered herein, contact the dealer from
whom you purchased the product.
3. Always be sure to include this manual when
selling, lending, or otherwise transferring the
ownership of this product.
4. Never allow children or anyone unable to fully
understand the directions given in the manual
to use the machine.
■ WORKING CONDITION
1. When using the product, you should wear proper
clothing and protective equipment.
(1) Helmet
(2) Ear protectors
(3) Protection goggles or face protector
(4) Thick work gloves
(5) Non-slip-sole work boots
2. And you should carry with you.
(1) Attached tools and files
(2) Properly reserved fuel
(3) Spare blade
(4) Things to notify your working area (rope,
warning signs)
(5) Whistle (for collaboration or emergency)
(6) Hatchet or saw (for removal of obstacles)
3. Do not wear loose clothing, jewelry, short
trousers, sandals, or go barefoot. Do not wear
anything which might be caught by a moving
part of the unit. Secure hair so it is above
shoulder length.
■ WORKING CIRCUMSTANCE
1. Never start the engine inside a closed room or
building. Exhaust gases contain dangerous
carbon monoxide.
2. Never use the product,
a. when the ground is slippery or when you can’t
maintain a steady posture.
7 
5. For safe operation
b. At night, at times of heavy fog, or at any other
times when your field of vision might be
limited and it would be difficult to gain a clear
view of the working area.
c. During rain storms, during lightning storms, at
times of strong or gale-force winds, or at any
other times when weather conditions might
make it unsafe to use the product.
■ WORKING PLAN
1. You should never use the product when under
the influence of alcohol, when suffering from
exhaustion or lack of sleep, when suffering from
drowsiness as a result of having taken cold
medicine or at any other time when a possibility
exists that your judgment might be impaired or
that you might not be able to operate the product
properly and in a safe manner.
2. When planning your work schedule, allow plenty
of time to rest. Limit the amount of time over
which the product is to be used continuously to
somewhere around 30~40 minutes per session,
and take 10~20 minutes of rest between work
sessions. Also try to keep the total amount of
work performed in a single day under 2 hours or
less.
WARNING
1. If you don’t observe the working time, or
working manner (See ■ USING THE
PRODUCT), Repetitive Stress Injury(RSI)
could occur.
If you feel discomfort, redness and swelling
of your fingers or any other part of your
body, see a doctor before getting worse.
2. To avoid noise complaints, in general,
operate product between 8a.m. and 5p.m. on
weekdays and 9a.m. to 5p.m. weekends.
NOTE
Check and follow the local regulations as to sound
level and hours of operations for the product.
8 
5. For safe operation
■ BEFORE STARTING THE ENGINE
1. The area within a perimeter of 50 feet (15m) of
the person using the product should be
considered a hazardous area into which no one
should enter. If necessary yellow warning rope,
warning signs should be placed around the
perimeter of the area. When work is to be
performed simultaneously by two or more
persons, care should also be taken to constantly
look around or otherwise check for the presence
and locations of other people working so as to
maintain a distance between each person
sufficient to ensure safety.
2. Check the condition of working area to avoid any
accident by hitting hidden obstacles such as
stumps, stones, cans, or broken grass.
IMPORTANT
Remove any obstacle before beginning work.
3. Inspect the entire unit for loose fasteners and
fuel leakage. Make sure that the cutting
attachment is properly installed and securely
fastened.
4. Be sure the debris guard is firmly attached in
place.
5. If the cutting head is the metal blade, use the
shoulder strap. Adjust the strap for comfort
before starting the engine. The strap should be
adjusted so the left hand can comfortably hold
the handlebar grip approximately waist high.
■ STARTING THE ENGINE
1. Keep bystanders and animals at least 50feet
(15m) away from the operating point. If you are
approached, immediately stop the engine.
2. The product is equipped with a centrifugal clutch
mechanism, so the cutting attachment begins to
rotate as soon as the engine is started by putting
the throttle into the start position. When starting
the engine, place the product onto the ground in
a flat clear area and hold it firmly in place so as
to ensure that neither the cutting part nor the
throttle come into contact with any obstacle
when the engine starts.
9 
5. For safe operation
WARNING
Never place the throttle into the high speed
position when starting the engine.
3. After starting the engine, check to make sure
that the cutting attachment stops rotating when
the throttle is moved fully back to its original
position. If it continues to rotate even after the
throttle has been moved fully back, turn off the
engine and take the unit to your authorized Red
Max servicing dealer for repair.
■ USING THE PRODUCT
IMPORTANT
Cut only materials recommended by the
manufacturer. And use only for tasks explained
in the manual.
1. Grip the handles firmly with both hands using
your whole hand. Place your feet slightly apart
(slightly further apart than the width of your
shoulders) so that your weight is distributed
evenly across both legs, and always be sure to
maintain a steady, even posture while working.
2. Keep cutting attachment below waist level.
3. Maintain the speed of the engine at the level
required to perform cutting work, and never raise
the speed of the engine above the level
necessary.
4. If the unit start to shake or vibrate, turn off the
engine and check the whole unit. Do not use it
until the trouble has been properly corrected.
5. Keep all parts of your body away from rotating
cutting attachment and hot surfaces.
6. Never touch the muffler, spark plug, or other
metallic parts of the engine while the engine is in
operation or immediately after shutting down the
engine. Doing so could result in serious burns or
electrical shock.
10 
5. For safe operation
• IF SOMEONE COMES
1. Guard against hazardous situations at all times.
Warn adults to keep pets and children away
from the area. Be careful if you are approached.
Injury may result from flying debris.
2. If someone calls out or otherwise interrupts you
while working, always be sure to turn off the
engine before turning around.
■ MAINTENANCE
1. In order to maintain your product in proper
working order, perform the maintenance and
checking operations described in the manual at
regular intervals.
2. Always be sure to turn off the engine before
performing any maintenance or checking
procedures.
WARNING
The metallic parts reach high temperatures
immediately after stopping the engine.
3. When replacing the cutting attachment or any
other part, or when replacing the oil or any
lubricant, always be sure to use only RedMax
products or products which have been
certified by RedMax for use with the RedMax
product.
4. In the event that any part must be replaced or
any maintenance or repair work not described in
this manual must be performed, please contact a
representative from the store nearest RedMax
authorized servicing dealer for assistance.
5. Do not use any accessory or attachment other
than those bearing the RedMax mark and
recommended for the unit.
6. Under no circumstances should you ever take
apart the product or alter it in any way. Doing so
might result in the product becoming damaged
during operation or the product becoming unable
to operate properly.
■ HANDLING FUEL
1. The engine of the RedMax product is designed
to run on a mixed fuel which contains highly
flammable gasoline. Never store cans of fuel or
11 
5. For safe operation
refill the tank of the unit in any place where there
is a boiler, stove, wood fire, electrical sparks,
welding sparks, or any other source of heat or
fire which might ignite the fuel.
2. Never smoke while operating the unit or refilling
its fuel tank.
3. When refilling the tank, always turn off the
engine and allow it to cool down. Take a careful
look around to make sure that there are no
sparks or open flames anywhere nearby before
refueling.
4. Wipe spilled fuel completely using a dry rag if
any fuel spillage occurs during refueling.
5. After refueling, screw the fuel cap back tightly
onto the fuel tank and then carry the unit to a
spot 10feet (3m) or more away from where it
was refueled before turning on the engine.
■ TRANSPORTATION
1. When hand-carrying the product, cover over the
cutting part if necessary, lift up the product and
carry it paying attention to the blade.
2. Never transport the product over rough roads
over long distances by vehicle without removing
all fuel from the fuel tank. If doing so, fuel might
leak from the tank during transport.
12 
6. Set up
SE1
SE2
SE3
■ INSTALLING HANDLE (SE1)
• Mount the handle to the shaft tube and clamp it
at your best operating position.
■ INSTALLING DEBRIS GUARD (SE2)
• Put the debris guard on the shaft tube near the
gear box, attach it with the screw, washer and
nut provided.
■ INSTALLING CUTTING HEAD (SE3)
1. While locking the gear shaft by inserting the
attached bar into the upper holder and the
housing.
2. Rotate the cutting head to engage threads.
Hand-tighten it securely.
13 
7. Fuel
WARNING
• Gasoline is very flammable. Avoid
smoking or bringing any flame or
sparks near fuel. Make sure to stop the
engine and allow it cool before
refueling the unit. Select outdoor bare
ground for fueling and move at least
3m (10ft) away from the fueling point
before starting the engine.
• The RedMax engines are lubricated by oil
specially formulated for air-cooled 2-cycle
gasoline engine use. If RedMax oil is not
available, use an anti-oxidant added
quality oil expressly labeled for air-cooled
2-cycle engine use. (JASO FC GRADE
OIL or ISO EGC GRADE)
• Do not use BIA or TCW (2-stroke watercooling type) mixed oil.
■ RECOMMENDED MIXING RATIO
GASOLINE 50:OIL 1
50:1 MIXING CHART
GASOLINE gal. 1
2
3
4
5
2-CYCLE OIL fl.oz 2.6 5.2 7.8 10.4 13
GASOLINE liter
2-CYCLE OIL ml
1
20
2
40
3
60
4
80
5
100
• Exhaust emission are controlled by the
fundamental engine parameters and
components(eq., carburation, ignition
timing and port timing) without
addition of any major hardware or the
introduction of an inert material during
combustion.
• These engines are certified to operate on
unleaded gasoline.
• Make sure to use gasoline with a
minimum octane number of 89 RON
(USA/Canada: 87AL)
• If you use a gasoline of a lower octane
value than prescribed, there is a danger
that the engine temperature may rise and
an engine problem such as piston seizing
may consequently occur.
• Unleaded gasoline is recommended to
reduce the contamination of the air for the
sake of your health and the environment.
• Poor quality gasolines or oils may damage
sealing rings, fuel lines or fuel tank of the
engine.
■ HOW TO MIX FUEL
IMPORTANT
Pay attention to agitation.
1. Measure out the quantities of gasoline
and oil to be mixed.
2. Put some of the gasoline into a clean,
approved fuel container.
3. Pour in all of the oil and agitate well.
4. Pour In the rest of gasoline and agitate
14 
7. Fuel
again for at least one minute. As some
oils may be difficult to agitate depending
on oil ingredients, sufficient agitation is
necessary for the engine to last long. Be
careful that, if the agitation is insufficient,
there is an increased danger of early
piston seizing due to abnormally lean
mixture.
5. Put a clear indication on the outside of the
container to avoid mixing up with gasoline
or other containers.
6. Indicate the contents on outside of
container for easy identification.
■ FUELING THE UNIT
1. Untwist and remove the fuel cap. Rest the
cap on a dustless place.
2. Put fuel into the fuel tank to 80% of the full
capacity.
3. Fasten the fuel cap securely and wipe up
any fuel spillage around the unit.
long period of time, clean the fuel tank
after rendering it empty. Next, activate the
engine and empty the carburetor of the
composite fuel.
6. In the case of scrapping the used mixed
oil container, scrap it only at an authorized
repository site.
NOTE
As lot details of quality assurance, read the
description in the section Limited Warranty
carefully. Moreover, normal wear and
change in product with no functional
influence are not covered by the warranty.
Also, be careful that, if the usage in the
instruction manual is not observed as to the
mixed gasoline, etc. described therein, it
may not be covered by the warranty.
WARNING
1. Select bare ground for fueling.
2. Move at least 10feet (3meters) away from
the fueling point before starting the
engine.
3. Stop the engine before refueling the unit.
At that time, be sure to sufficiently agitate
the mixed gasoline in the container.
FOR YOUR ENGINE LIFE, AVOID;
1. FUEL WITH NO OIL(RAW GASOLINE) –
It will cause severe damage to the internal
engine parts very quickly.
2. GASOHOL – It can cause deterioration of
rubber and/or plastic parts and disruption
of engine lubrication.
3. OIL FOR 4-CYCLE ENGINE USE – It can
cause spark plug fouling, exhaust port
blocking, or piston ring sticking.
4. Mixed fuels which have been left
unused for a period of one month or
more may clog the carburetor and result
in the engine failing to operate properly.
5. In the case of storing the product for a
15 
8. Operation
■ STARTING ENGINE
OP1
WARNING
The cutting head will start rotating upon the
engine starts.
OP2
(1)
A (2)
1. Rest the unit on a flat, firm place. Keep the
cutting head off the ground and clear of
surrounding objects as it will start rotating upon
starting of the engine.
2. Push the primer pump several times until
overflown fuel flows out in the return tube. (OP1)
3. Move the choke lever to the closed position.
(OP2)
(1) Choke lever
(2) A: the closed position
(3) B: the open position
B (3)
OP3
4. Set the ignition switch to the “start” position.
(OP3)
(1) Ignition switch
(3) Start
(2) Stop
5. While holding the unit firmly, pull out the starter
rope quickly until engine fires. (OP4)
OP4
IMPORTANT
• Avoid pulling the rope to its end or returning it by
releasing the knob. Such actions can cause
starter failures.
6. Move the choke lever to the open position
(OP2). And pull out the starter rope quickly to
restart engine. (OP4)
7. Allow the engine to warm up for several minutes
before starting operation.
NOTE
1. When restarting the engine immediately after
stopping it, leave the choke open (OP2) and
push the primer pump several times (OP4).
2. Overchoking can make the engine hard to start
due to excess fuel. When the engine failed to
start after several attempts, open the choke and
repeat pulling the rope, or remove the spark plug
and dry it.
16 
8. Operation
■ STOPPING ENGINE
1. Release the throttle lever and run the engine for
a half minute.
2. Shift the ignition switch to the STOP position.
NOTE
• Except for an emergency, avoid stopping the
engine while pulling the throttle lever.
OP5
(1)
■ ADJUSTING IDLING SPEED (OP5)
1. When the engine tends stop frequently at idling
mode, turn the adjusting screw clockwise.
2. When the cutting head keeps rotating after
releasing the trigger, turn the adjusting screw
counter-clockwise.
(1) Idle adjustment screw
NOTE
• Warm up the engine before adjusting the idling
speed.
■ LINE HEAD USAGE
WARNING
OP6
1. Always wear eye protection such as safety
goggles. Never lean over the rotating cutting
head. Rocks or other debris could be thrown
into eyes and face and cause serious
personal injury.
2. Keep the debris guard attached in place at all
times when the unit is operated.
TRIMMING GRASS AND WEEDS
• Always remember that the TIP of the line does
cutting. You will achieve better results by not
crowding the line into the cutting area. Allow the
unit to trim at its own pace.
1. Hold the unit so the head is off the ground and is
tilted about 20 degrees toward the sweep
direction. (OP6)
2. You can avoid thrown debris by sweeping from
your right to the left.
17 
8. Operation
3. Use a slow, deliberate action to cut heavy
growth. The rate of cutting motion will depend on
the material being cut. Heavy growth will require
slower action than will light growth.
4. Never swing the unit so hard as you are in
danger of losing your balance or control of the
unit.
5. Try to control the cutting motion with the hip
rather than placing the full workload on the arm
and hands.
6. Take precautions to avoid wire, grass and dead,
dry, long-stem weeds from wrapping around the
head shaft. Such materials can stall the head
and cause the clutch to slip, resulting in damage
to the clutch system if repeated frequently.
ADJUSTING THE LINE LENGTH
• Your brushcutters is equipped with a semi- auto
type nylon line head that allows the operator to
advance the line without stopping the engine.
When the line becomes short, lightly tap the
head on the ground while running the engine at
full throttle.
• Each time the head is bumped, the line advance
about 1 inch(25.4 mm). For better effect, tap the
head on bear ground or hard soil. Avoid
bumping in thick, tall grass as the engine may
stall by overload.
18 
9. Maintenance
Maintenance, replacement, or repair of the emission control device and systems may be
performed by any non-road engine repair establishment or individual.
WARNING
• Always be sure to stop the engine before inspecting the brushcutter for problems or
performing maintenance.
• Never alter the brushcutter or take the engine apart.
• When replacing parts, always be sure to use only RedMax products or products which
have been certified by RedMax for use with the RedMax brushcutter.
• Things to check before using brushcutter.
■ REFILLING TRIMMING LINE
1
4
6
2
5
7
3.8m
(12.5')
Ø2.4mm
0.095In
3
7.6m
(25')
19 
9. Maintenance
8
11
WIND
LINE
14
THIS
SIDE UP
1
2
9
10
12
13
20 
THIS
SIDE UP
15
9. Maintenance
WARNING
• Make sure that the engine has stopped and is
cool before performing any service to the
brushcutter. Contact with moving cutting
head or hot muffler may result in a personal
injury.
MA1
(1)
■ AIR FILTER
• The air filter, if clogged, will reduce the engine
performance. Monthly check and clean the filter
element in warm, soapy water as required. Dry
completely before installing. If the element is
broken or shrunk, replace with a new one. (MA1)
(1) Air filter
MA2
■ FUEL FILTER
• When the engine runs short of fuel supply, check
the fuel cap and the fuel filter for blockage.
(MA2)
(1) Fuel filter
MA3
■ SPARK PLUG
• Starting failure and mis-firing are often caused
by a fouled spark plug. Periodically clean the
spark plug and check that the spark gap is in the
correct range. For a replacement plug, use the
correct type specified by RedMax(See SPECIFICATIONS on the page 4). (MA3)
• When you take off the spark plug, twist (1) and
pull off the cap (2). (MA4)
• REPLACEMENT PLUG IS A CHAMPION
RCJ6Y OR THE EQUIVALENT, SUCH AS
BOSCH WSR8E OR NGK BPMR7A.
MA4
IMPORTANT
• Note that using any spark plugs other than those
designated may result in the engine failing to
operate properly or in the engine becoming
overheated and damaged.
• To install the spark plug, first turn the plug until it
is finger tight, then tighten it a quarter turn more
with a socket wrench.
87~104 in-lbs
TIGHTENING TORQUE:
(9.8~11.8 N.m.)
21 
9. Maintenance
■ MUFFLER
WARNING
• Inspect periodically, the muffler for loose
fasteners, any damage or corrosion. If any
sign of exhaust leakage is found, do not use
the brushcutter and have it repaired
immediately.
• Note that failing to do so may result in the
engine catching on fire.
MA5
(1)
■ SPARK ARRESTER
• The muffler is equipped with a spark arrester to
prevent red hot carbon from flying out of the
exhaust outlet. Periodically inspect and clean as
necessary with a wire brush. In the State of
California it is required by law (Section 4442 of
the California Public Resources Code) to equip a
spark arrester when a gas powered tool is used
in any forest covered, brush covered, or grass
covered unimproved land. (MA5)
(1) Spark arrester
■ INTAKE AIR COOLING VENT
WARNING
• Never touch the cylinder, muffler, or spark
plugs with your bare hands immediately after
stopping the engine. The engine can
become very hot when in operation, and
doing so could result in severe burns.
• When checking the brushcutter to make sure
that it is okay before using it, check the area
around the muffler and remove any wood
chips or leaves which have attached
themselves to the brushcutter. Note that
failing to do so could cause the muffler to
become overheated, and that this in turn
could cause the brushcutter to catch on fire.
Always make sure that the muffler is clean
and free of wood chips, leaves, and other
waste before use.
• Check the intake air cooling vent and the area
around the cylinder cooling fins after every 25
22 
9. Maintenance
hours of use for blockage, and remove any
waste which has attached itself to the
brushcutter. Note that it is necessary to remove
the plug guard shown in Figure 20 in order to be
able to view the upper part of the cylinder.
IMPORTANT
MA6
• If waste gets stuck and causes blockage around
the intake air cooling vent or between the
cylinder fins, it may cause the engine to
overheat, and that in turn may cause mechanical
failure on the part of the brushcutter. (MA6)
(1)
(1) Cylinder fin
(2) Intake air cooling vent (back)
(2)
■ PROCEDURES TO BE PERFORMED AFTER
EVERY 100 HOURS OF USE
1. Remove the muffler, insert a screwdriver into the
vent, and wipe away any carbon buildup. Wipe
away any carbon buildup on the muffler exhaust
vent at the same time. (MA7)
MA7
(1)
(2)
(1) Screwdriver
(2) Muffler
2. Tighten all screws, bolts, and fittings.
3. Check to see if any oil or grease has worked its
way in between the clutch lining and drum, and if
it has wipe it away using oil-free, lead-free
gasoline.
23 
10. Storage
• Aged fuel is one of major causes of engine
starting failure. Before storing the unit, empty the
fuel tank and run the engine until it uses all the
fuel left in the fuel line and the carburetor. Store
the unit indoor taking necessary measures for
rust prevention.
11. Troubleshooting guide
Case 1. Starting failure
CHECK
fuel tank
fuel filter
carburetor adjustment screw
sparking (no spark)
spark plug
➞
➞
➞
➞
➞
➞
PROBABLE CAUSES
incorrect fuel
fuel filter is clogged
out of normal range
spark plug is fouled/wet
plug gap is incorrect
disconnected
➞
➞
➞
➞
➞
➞
ACTION
drain it and with correct fuel
clean
adjust to normal range
clean/dry
correct (GAP: 0.6~0.7mm)
retighten
Case 2. Engine starts but does not keep running/Hard re-starting.
CHECK
fuel tank
carburetor adjustment screw
muffler,cylinder (exhaust port)
air cleaner
cylinder fin, fan cover
➞
➞
➞
➞
➞
PROBABLE CAUSES
incorrect fuel or staled fuel
out of normal range
carbon is built-up
clogged with dust
clogged with dust
➞
➞
➞
➞
➞
ACTION
drain it and with correct fuel
adjust to normal range
wipe away
wash
clean
When your unit seems to need further service, please consult with our RedMax service shop in your area.
24 
12. Parts list
LINE TRIMMER
BT250
NOTE :
1. Use KOMATSU ZENOAH genuine parts as specified in the parts list for repair and/or
replacement.
2. KOMATSU ZENOAH does not warrant the machines, which have been damaged by the
use of any parts other than those specified by the company.
3. When placing parts orders for repair and/or replacement, check if the model name and the
serial number are applicable to those specified in the parts list, then use parts number
described in the parts list.
4. The contents described in the parts list may change due to improvement.
5. The parts for the machine shall be supplied seven (7) years after the machine is
discontinued. [It is possible that some specific parts may be subject to change of their
delivery term and list price within the limit of seven (7) years after the machine is
discontinued. It is also possible that some parts may be available even after the limit of
seven (7) years.]
March. 2004
APPLICABLE SERIAL NUMBERS :
DRIVE UNIT 40400101 and up
ENGINE UNIT KU40001 and up
25 
12. Parts list
Fig.1 DRIVE UNIT BT250 (S/N 40400101 and up)
26 
Fig.1 DRIVE UNIT BT250 (S/N 40400101 and up)
Key# Part Number
Description
1 BT25-50810 PIPE COMP.
2 BT25-50710 DRIVE SHAFT
3 BT25-50910 HOUSING ASSY
4 BT25-50610 GRIP
5 BT25-50510 LEVER ASSY
6 BT25-50520 SCREW
7
1855-82100 CABLE ASSY
8 BT25-80100 TUBE
9 BT25-50400 HANDLE ASSY
10 BT25-50410 • HANDLE
11
0263-90530 • SCREW
12 B1181-000504 • NUT
13 BT25-80810 GUARD ASSY
14 BT25-80840 • GUARD
15 01000-69820 • BOLT
16 00311-06000 • WASHER
17 00217-06000 • NUT
18 BT25-80830 • BLADE
19 01500-69830 • SCREW
20 BT25-90910 PLATE, name
21 BT25-90810 SPACER
22 BT25-90100 TAP HEAD
23 T3002-91190 GOGGLE
Q'ty
Key# Part Number
Description
Q'ty
1
1
1
1
1
1
1
1
1
1
3
3
1
1
1
1
1
1
1
1
1
1
1
27 
12. Parts list
Fig.2 ENGINE UNIT BT250 (S/N KU40001 and up)
28 
Fig.2 ENGINE UNIT BT250 (S/N KU40001 and up)
Key# Part Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
6634401
3075406
6635301
6969601
3075603
6969501
6968901
6457403
4309501
6968501
5987501
9071301
6968401
5687401
6634801
3075003
3090101
6457303
6969001
6969101
6968701
6997001
6230101
6968801
4300401
6634701
3074802
6300206
6457003
9071102
6634502
5994702
9071103
6634402
3074502
6970001
6969901
5688002
3078001
3097402
6634501
5994601
4315001
5945801
6634601
5687301
Description
Q'ty
SCREW
FRONT HOUSING
SCREW CLUTCH
WASHER CURVED
CLUTCH ASSY
WASHER PLAIN
NUT
ROTOR
CRANKCASE&SHAFT ASSY
• BEARING
• SEAL
GASKET CASE
• RING
• SEAL
• SCREW
• CRANKCASE ASSY
CRANKSHAFT ASSY
PISTON
RING
CLIP RING
WASHER
NEEDLE BEARING
WRIST PIN
KEY
PULLEY ASSY
BOLT MAFFLER
MUFFLER & arrester
MUFFLER GASKET
CYLINDER
GASKET INSULATOR
SCREW TORX
INSULATOR
GASKET CABURETOR
SCREW TORX
CARBURETOR
CLIP HOSE
CLIP HOSE
PLASTIC RUBBER TUBING
PRIMER ASSY
CHOKE LEVER&PLATE ASSY
• SCREW TORX
• CHOKE PLATE
• CARBURETOR PLATE
• CHOKE LEVER
BOLT CARBURETOR
ELEMENT
4
1
2
2
1
2
1
1
1
2
1
1
1
1
3
1
1
1
2
2
2
1
1
1
1
2
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
2
1
Key# Part Number
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
3099904
5946101
9506501
9506009
9506011
8714402
6634201
6635102
6300221
9070901
5947001
6656301
3075304
6635101
9506401
9506010
9509001
3075804
3075705
3075904
5687901
5688001
5687801
5835901
6976501
3075803
6635401
6634901
2917803
2914301
2914302
5946201
6996901
848-EU0-53D0
01252-30630
1565-12140
2630-31950
1484-86280
5883-32160
Description
COVER ASSY
KNOB
DECAL
DECAL(To Start)
DECAL(caution)
SPARK PLUG
CAP SCREW
SCREW TORX
PLATE FIN
GASKET CYLINDER
REAR HOUSING
SCREW TORX
RECOIL ASSY
SCREW TORX
DECAL STARTER
DECAL(E Start)
DECAL(EMISSION)
TANK&CAP ASSY
• TANK ASSY
• • FILTER
• • PlPE RETURN
• • PlPE FUEL
• • TANK GROMMET
• • TANK
• • CLIP
• CAP ASSY
BOLT TORX
BOLT TORX
COIL&BOOT ASSY
LEAD ASSY(BLACK)
LEAD ASSY(RED)
SPACER
WASHER
CUSHION
BOLT
NUT
SCREW
WASHER
SCREW
Q'ty
1
1
1
1
1
1
2
2
1
2
1
3
1
4
1
1
1
1
1
1
1
1
1
1
1
1
3
2
1
1
1
2
2
1
1
1
1
1
1
29 
RedMax
LIMITED WARRANTY
EMISSION-RELATED PARTS, FOR TWO (2) YEARS FROM THE DATE OF ORIGINAL DELIVERY OF THE UNIT,
KOMATSU ZENOAH AMERICA INC. (THE COMPANY),
THROUGH ANY RedMax DEALER, WILL REPAIR OR REPLACE, FREE OF CHARGE, FOR THE ORIGINAL AND EACH
SUBSEQUENT PURCHASER, ANY PART OR PARTS FOUND TO BE DEFECTIVE IN MATERIAL AND/OR
WORKMANSHIP. EMISSION-RELATED PARTS ARE:
THE CARBURETOR ASSY, COIL ASSY, ROTOR, SPARKPLUG,
AIR FILTER, FUEL FILTER, INTAKE MANIFOLD, AND THE GASKETS
ALL OTHER PARTS EXCEPT ABOVE PARTS, FOR TWO (2) YEARS OF HOME USE, NINETY (90) DAYS FOR COMMERCIAL
USE FROM THE DATE OF ORIGINAL PURCHASE, THE COMPANY, THROUGH RedMax DEALER, WILL REPAIR OR
REPLACE, FREE OF CHARGE, FOR THE ORIGINAL PURCHASER, ANY PART OF PARTS FOUND TO BE DEFECTIVE IN
MATERIAL AND/OR WORKMANSHIP. THIS IS THE EXCLUSIVE REMEDY.
THE PURCHASER SHALL BEAR COSTS OF TRANSPORTING THE UNIT TO AND FROM THE RedMax DEALER.
THE PURCHASER SHALL NOT BE CHARGED FOR DIAGNOSTIC LABOR WHICH LEADS TO THE DETERMINATION
THAT A WARRANTED PART IS DEFECTIVE, IF THE DIAGNOSTIC WORK IS PERFORMED AT THE RedMax DEALER.
THE PURCHASER OR OWNER IS RESPONSIBLE FOR THE PERFORMANCE OF THE REQUIRED MAINTENANCE AS
DEFINED BY THE MANUFACTURER IN THE OWNER/OPERATOR MANUAL.
ANY WARRANTED PART WHICH IS NOT SCHEDULED FOR REPLACEMENT AS REQUIRED MAINTENANCE, OR
WHICH IS SCHEDULED ONLY FOR REGULAR INSPECTION TO THE EFFECT OF "REPAIR OR REPLACE AS
NECESSARY" SHALL BE WARRANTED FOR THE WARRANTY PERIOD.ANY WARRANTED PART WHICH IS
SCHEDULED FOR REPLACEMENT AS REQUIRED MAINTENANCE SHALL BE WARRANTED FOR THE PERIOD OF
TIME UP TO THE FIRST SCHEDULED REPLACEMNET POINT FOR THE PART.
ANY REPLACEMENT PART THAT IS EQUIVALENT IN PERFORMANCE AND DULABILITY MAY BE USED IN NONWARRANTY MAINTENANCE OR REPAIRS, AND SHALL NOT REDUCE THE WARRANTY OBLIGATION OF THE
COMPANY.
THE COMPANY IS LIABLE FOR DAMAGES TO OTHER ENGINE COMPONENTS CAUSED BY THE FAILURE OF A
WARRANTED PARTS STILL UNDER WARRANTY.
THE WARRANTY DOES NOT APPLY TO THOSE UNITS WHICH HAVE BEEN DAMAGED BY NEGLIGENCE OF
INSTRUCTION LISTED IN THE OWNER/OPERATOR MANUAL FOR PROPER USE AND MAINTENANCE OF THE UNITS,
ACCIDENTAL MISHANDLING, ALTERATION, ABUSE, IMPROPER LUBULICATION, USE OF ANY PARTS OR ACCESSARIES
OTHER THAN THOSE SPECIFIED BY THE COMPANY, OR OTHER CAUSES BEYOND THE CONPANY'S CONTROL.
THIS WARRANTY DOES NOT COVER THOSE PARTS REPLACED BY NORMAL WEAR OR HARMLESS CHANGES IN
THEIR APPEARANCE.
THERE ARE NO OTHER EXPRESS WARRANTIES.
IMPLIED WARRANTIES INCLUDING THOSE OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE LIMITED TO TWO (2) YEARS HOME OF USE, NINETY (90) DAYS FOR COMMERCIAL USE FROM THE ORIGINAL
DELIVERY DATE.
LIABILITIES FOR INCIDENTAL OR CONSEQUENTIAL DAMAGE UNDER ANY AND ALL WARRANTIES
ARE EXCLUDED.
SOME STATES DO NOT ALLOW LIMITATION ON HOW LONG AN IMPLIED WARRANTY LASTS OR EXCLUSION OR
LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMINATION OR EXCLUSION MAY
NOT APPLY TO YOU.
THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY
FROM STATE TO STATE.
IF YOU NEED TO OBTAIN INFORMATION ABOUT THE NEAREST SERVICE CENTER, PLEASE CALL KOMATSU
ZENOAH AMERICA INC. AT (770)-381-5147.
IMPORTANT: YOU WILL RECEIVE A WARRANTY REGISTRATION CARD AT TIME OF PURCHASE.PLEASE FILL
OUT THE CARD AND SEND IT TO RedMax / KOMATSU ZENOA AMERICA WITHIN SEVEN (7) DAYS.BE SURE TO KEEP
A COPY FOR YOUR RECORDS.
KOMATSU ZENOAH AMERICA INC.
4344 Shackleford Road Suite 500
Norcross, Georgia 30093
RedMax
Garantie limitée
Pièces en rapport avec les émissions de gaz d'échappement : KOMATSU ZENOAH AMERICA INC., par
l'intermédiaire de n'importe quel revendeur RedMax, réparera gratuitement ou remplacera gratuitement pour
l'acheteur initial et chaque acheteur successif toute(s) pièce(s) se révélant de constitution et/ou de montage
défectueux pendant deux (2) ans à compter de la date initiale de livraison d’une unité. Les pièces en rapport avec les
émissions de gaz d'échappement sont:
l'assemblage carburateur, l'assemblage bobine, le rotor, la bougie,
le filtre à air, le filtre à carburant, la tubulure d'admission et les joints
Toutes les pièces autres que celles mentionnées ci-dessus, deux (2) ans d'utilisation domestique, quatre-vingtdix (90) jours d'utilisation commerciale, à compter de la date d'achat initial. La société, par l'intermédiaire d'un
distributeur RedMax, réparera ou remplacera toute(s) pièce(s), sans frais et au bénéfice de l'acheteur original, en
prenant en charge les frais de pièces et/ou de main d'œuvre. Telles sont les limites de la garantie.
Le coût du transport de l'unité jusqu'au revendeur RedMax et depuis celui-ci sera à la charge de l'acheteur.
L'acheteur ne supportera pas le coût de main d'oeuvre du diagnostic qui amène à la conclusion qu'une pièce
garantie est défectueuse, si ce diagnostic est effectué chez le revendeur RedMax.
L’acheteur ou propriétaire a pour responsabilité d’effectuer l’entretien obligatoire tel que défini par le fabricant dans le
manuel du propriétaire/de l'utilisateur.
Toute pièce garantie dont le remplacement n'est pas prévu dans le cadre de l’entretien obligatoire, ou pour laquelle
est seulement prévue une inspection périodique pour "remplacement ou réparation si nécessaire" sera garantie pour
la période de garantie. Toute pièce garantie arrivée à l’échéance de son premier remplacement prévu sera garantie
jusqu’à celui-ci.
Toute pièce de rechange équivalente en performance ou en durabilité peut être utilisée pour l’entretien hors-garantie
ou les réparations hors-garantie, et ce sans réduire l’obligation de garantie incombant à la société.
La société sera tenue responsable des dommages aux autres composants du moteur causés par la défaillance de
pièce(s) garantie(s) en période de garantie.
La garantie ne s'applique pas aux unités endommagées par suite de: négligence dans la mise en oeuvre des
instructions spécifiées dans le manuel du propriétaire/de l'utilisateur en vue d’une utilisation et d’un entretien correct,
fausse manœuvre accidentelle, modification, utilisation abusive, lubrification incorrecte, utilisation de pièces ou
d’accessoires autres que ceux spécifiés par la société, ou autres causes hors du contrôle de la société.
Cette garantie ne couvre pas les pièces remplacées en raison de leur usure normale ou de changements
d’apparence sans effets.
Il n'existe aucune autre garantie explicite.
Les garanties implicites, y compris la valeur marchande et la valeur d'usage pour une utilisation particulière, sont
limitées deux (2) ans d'utilisation domestique, quatre-vingt-dix (90) jours d'utilisation commerciale, à compter de la
date originale de livraison.
Les responsabilités pour les dommage conséquents ou incidents sont exclues de toutes les garanties.
Certaines provinces n'autorisant pas les limitations à la durée des garanties implicites, ou les exclusions ou
limitations relatives aux dommages incidents ou conséquents, la limitation indiquée ci-dessus peut ne pas vous être
applicable.
Cette garantie vous donne des droits juridiques spécifiques, et vous pouvez également jouir d’autres droits variant
d'une province à l'autre.
Si vous désirez obtenir des informations sur le centre de service le plus proche, veuillez appeler KOMATSU
ZENOAH AMERICA INC. au (770)-381-5147
Note importante: vous recevrez une carte d'enregistrement de garantie au moment de l'achat. Veuillez la remplir et
l'adresser à RedMax / KOMATSU ZENOAH AMERICA sous sept (7) jours en prenant soin de conserver une copie
pour vous.
KOMATSU ZENOAH AMERICA INC.
4344 Shackleford Road Suite 500
Norcross, Georgia 30093
Printed in U.S.A.