Makita EM4350UH Manual

PRODUCT
P 1/ 2
Straight unleaded gasoline
Yes
43.0 (2.6)
Models No.
Description
CONCEPT AND MAIN APPLICATIONS
Specification
Standard equipment
Optional accessories
EM4350UH, EM4350LH
EM4351UH
Petrol Brushcutter
Primer pump
Engine
Displacement: cm³ (cu.in.)
Fuel
4-stroke
Specifications EM4350LH
Model
Type
Loop handleHandle style
Engine oil
Carburetor
SAE10W-30 oil
in the Class SF or higher of API Classification
(Automotive 4-stroke engine oil)
Diaphragm
These models are 43.0cm³ 4-stroke petrol brushcutters developed
in compliance with well-known exhaust emission regulations.
Their main features are:
•Powerful 4-stroke engine for working in larger open area, and
for easily cutting through thick weeds and longer grass
• Newly designed throttle assembly with wide-grip throttle trigger
• Universal guard for both metal blade and nylon cutting head
• Toolless quick fastening handle holder for easy handling and
angle adjustment of handle(for EM4350UH, EM4351UH only)
• Floating structure with four rubber buffers absorbs vibration
transmitted from engine to bike handle. (for EM4351UH only)
Net weight*1: kg (lbs) 7.9 (17.3)
*1 Dry weight, without universal guard, cutting tool and shoulder harness
Note: The standard equipment for the tool shown above may vary by country.
Blade or Nylon cutting head ..................... 1
Universal guard (=Protector) .................... 1
Blade cover ............................................... 1 (for the model with blade)
Double shoulder straps with waist pad ..... 1 (for EM4350UH)
Double shoulder straps with waist pad
for Loop handle model...... 1 (for EM4350LH)
Double shoulder straps with waist belt ..... 1 (for EM4351UH)
Tool set (Hex wrench 4, Hex wrench 5,
Socket wrench 16-17,
Socket driver 16-10) .................. 1
Accessory bag ............................................ 1
Oil bottle without oil or
Oil bottle containing 100mL engine oil ..... 1
255mm Triple blade, 300mmTriple blade, 255mm Star blade, 200mm Chisel blade, 225mm Chisel blade,
Nylon cutting heads (UltraAuto 6), Protector, Protector extension, Protector 200 set, Protector 225 set,
Double shoulder straps, Oil bottle
635 (25) 339 (13-3/8) 618 (24-1/4)
Dimensions: mm (")
Width (W)
Height (H)
Length (L) 1,812 (71-1/2)
The drawing
above is
EM4350UH.
1,812 (71-1/2)
460 (18-1/8) 528 (20-3/4)250 (9-7/8)
EM4350UH EM4350LH EM4351UH
Anti-vibration system
EM4351UHEM4350UH
Bike handle
8.3 (18.2)
Conventional low-vibration structure
Yes
1.50 (2.1) at 7,500 rpm
Engine start assist Yes
(by automatic mechanical decompression valve)
7,200
Bike handle
Floating structure
8.6 (18.9)
Clutch
0.62 (21.0)Fuel tank capacity: L (US oz)
M10x1.25, Left-handedSpindle thread size
L
EM4350UH
EM4351UH
H
W
EM4350LH
L
W
H
Max. spindle speed at no load: min.ˉ¹ = rpm
Max. torque: N.m
Max. output: kW (PS)
2.1 at 5,500 rpm
TECHNICAL INFORMATION

CAUTION: Repair the machine in accordance with “Instruction manual” or “Safety instructions”.
[4] DISASSEMBLY/ASSEMBLY
[4]-1. Warning
Follow the instructions described below in advance before repairing:
• Wear gloves.
• Remove the cutting tool from the unit, and if it is a saw blade, attach the blade cover to the blade.
• When the engine is hot from use, cool down the engine enough or you can get burned.
• Remove remaining fuel from Fuel tank and Carburetor completely. [FLAMMABLE MATERIAL KEEP FIRE AWAY]
• Remove Spark plug cap from Spark plug.
• Repair the engine on a stable workbench and in a clean workplace kept as free of dust and debris as possible.
• In order to avoid wrong reassembly, draw or write down where and how the parts are assembled, and what are the parts.
It is also recommended to have boxes ready to keep disassembled parts by group.
• Handle the disassembled parts carefully. Clean and wash them properly.
• If some bolts and screws are too tight, use an impact driver.
• Tighten the bolts and the screws to the specified torque as shown in "[4]-15. Tightening torque specifications".
• Each time after you mounted a main part of the engine such as the piston, check if it moves smoothly
without abnormal noise by manually turning the crankshaft.
• After completion of reassembly, check for loose parts or abnormal noise and vibration
by manually turning the crankshaft.
[2] HANDLING OF GASKET
[3] LUBRICANT / ADHESIVE APPLICATION
Repair
P / 2
[1] NECESSARY REPAIRING TOOLS
DescriptionCode No. Use for
Once Gasket is removed:
(1) Clean up the mating surface where the gasket was installed to maintain its sealing performance.
(2) Replace it with a new one.
(1) Apply a little amount of Makita grease N No. 2 to Spiral spring in Recoil starter and the spline ends of Shaft in
Shaft pipe complete.
(2) When the inside of Gear case is cleaned, supply 11g of Makita grease N No. 2 from the grease inlet.
(3) Apply 4g of Makita grease N No. 1 to the entire portion of Shaft in Shaft pipe complete.
(4) Once Engine is disassembled, remove oil/grease from the mating surface of Cylinder and Crankcase complete,
then apply ThreeBond 1215/1216 to the mating surface for the reassembly.
Retaining ring pliers ST-2 for External ring1R004
press-fitting Cutter shaft set into Ball bearing 6000DDU
press-fitting Clutch drum into Ball bearing 6004LLU/6003LLU
Bearing setting pipe 20-12.21R028
removing Spiral bevel gear 14 from Ball bearing 609ZZ
Bearing setting pipe 28-20.21R031
removing/ installing Retaining rings
Retaining ring pliers RT-2N for Internal ring1R005 removing/ installing Cotter by using 1R389
removing Ball bearing 6000DDU from Cutter shaft completeBearing setting plate 10.21R033
removing Ball bearingsGear extractor (Large)1R045
Retaining ring pliers RT-2E for Internal ring1R006 removing/ installing Retaining rings
Air density tester1R127 diagnosing Carburetor
Round bar for arbor 20-1001R247 removing Clutch drum complete from Clutch case
Round bar for arbor 8-501R282
removing Spiral bevel gear 14 from Ball bearing 6000ZZ and
6000
removing Piston pin
Round bar for arbor 12-501R286 press-fitting Clutch drum complete into Clutch case
Retaining ring S and R pliers1R291 removing/ installing Retaining rings
Torque wrench shaft 7-23N.m tightening Bolts to specified torque 1R219
Torque wrench shaft 2-6N.m1R254
Flywheel puller1R364 removing Flywheel
Feeler gauge set1R366 adjusting Ignition coil, Spark plug
Cotter removal attachment1R389 removing/ installing Cotter by using 1R005
10mm Hex socket bit
--- removing/ installing Flywheel
14mm Hex socket bit
--- removing/ installing Clutch
Wire brush
--- cleaning Spark plug

[4] DISASSEMBLY/ASSEMBLY
[4]-2. Engine and Shaft
Repair
P / 2
(1) Press down the tab of Cleaner plate assembly gently and separate Cleaner cover assembly from Cleaner plate assembly
by loosening M5x20 Hex socket head bolt. (Fig. 1)
(2) Loosen 5x16 Tapping screw and loosen Clamp that holds Bullet terminals near Cleaner plate assembly. (Fig. 2)
(3) Disconnect Bullet terminals of Earth wire and Primary wire of Ignition coil from the wires of Stop switch. (Fig. 2)
(4) Remove Control cable from Swivel of Carburetor; loosen the three nuts on Control cable to release the tension
between Swivel and Cable bracket of Insulator, then remove the stopper on Inner cable end from Swivel. (Fig. 3)
(5) For EM4351UH: Remove M5x8 Hex socket head bolt and M6x30 Hex socket head bolt in the holes of Pipe housing.
(Fig. 4)
For EM4350UH and EM4350LH: Remove M5x8 Hex socket head bolt and M6x30 Hex socket head bolt from
the threaded holes of Clutch case. (Fig. 5)
(6) Grab Shaft pipe complete by hand, then pull it off from Clutch case.
If Shaft sticks in Clutch case, use water pump pliers or the like to pull it off.
Note: Be sure to wrap Shaft with a rag or the like to protect it from water pump pliers. (Fig. 6)
Clamp
Cleaner plate assemblySwivel of Carburetor
Inner cable
5x16
Tapping
screw
M5x8
Hex socket
head bolt
M5x8 Hex socket
head bolt
M6x20
Hex socket
head bolt
M6x20 Hex
socket head bolt
Holes of
Pipe housing
Threaded holes
of Clutch case
M5x20 Hex socket
head bolt
Control cable
Fig. 1
Fig. 5 Fig. 6
Fig. 3 Fig. 4
Fig. 2
Tab of
Cleaner plate assembly
Cleaner cover
assembly
Bullet terminals
Cable bracket of Insulator
Stopper on Inner cable end
Nut on Control cable end
(3 pcs.)
Swivel of Carburetor
ShaftRag
Water pump
pliers
Shaft pipe complete

[4] DISASSEMBLY/ASSEMBLY
[4]-2. Engine and Shaft (cont.)
Repair
P / 2
Assemble by reversing the disassembly procedure.
(1) Put Cable bracket between Flat washer 6 and middle Nut, and tighten them by turning lower nut, upper nut and
the middle nut. (Fig. 7)
(2) Put Stopper on Inner cable end into Swivel, then adjust the above nuts so that 3mm to 4mm of play is left inside of
Swivel under condition that Throttle lever is not pulled. (Fig. 7)
Note: Adjust the tension of Inner cable to prevent the stopper from being removed . (Fig. 7)
(1) Loosen two M6x30 Hex. socket head bolt (2pcs.) and remove Protector with Protector extension attached. (Fig. 8)
(2) Enlarge the space between the side wall of Protector cover and M5x14 Hex socket head bolt, and remove Protector cover
from Shaft pipe complete. (Fig. 9)
(3) Remove two M5x14 Hex socket head bolts then remove Protector clamp.
(4) Loosen M6x30 Hex socket head bolt then remove Gear case assembly. (Fig. 10)
Fig. 7
Play: 3mm to 4mm
Cable bracket of Insulator
complete
Stopper on Inner cable end
ASSEMBLING
DISASSEMBLING
Nut (lower)
Nut (upper)
Nut (middle)
Flat washer 6 Swivel
[4]-3. Shaft pipe complete
Fig. 8
M6x30 Hex. socket
head bolt (2 pcs.)
Protector
Protector clamp
Gear case
assembly
Shaft pipe
complete
M5x14 Hex socket head bolt (2 pcs.)
M6x30 Hex
socket head bolt
Protector extension
Gear case assembly
M5x14 Hex socket
head bolt (2 pcs.)
Fig. 9
Fig. 10
The side wall of
Protector cover

[4] DISASSEMBLY/ASSEMBLY
[4]-3. Shaft pipe complete (cont.)
Repair
P / 2
For 4351UH:
(5A) Loosen M5x18 Hex socket head bolt and remove Shaft pipe complete from Pipe housing. (Fig. 11)
(6A) Pull out Shaft from Shaft pipe complete.
For 4350UH:
(5B) Remove two M6x25 Hex socket head bolts and Pipe clamp, then separate Bike handle section from Shaft pipe
complete. (Fig. 12)
(6B) Remove the following parts from Shaft pipe complete.
• Wire clamp (2 pcs.) • Hanger set • Shaft (Fig. 13)
For 4350LH:
(5C) Remove four M5x30 Hex socket head screws, then remove Handle clamp 28 and then remove Loop handle 28.
(Fig. 14)
(6C) Loosen two M5x14 Hex socket head bolts, then separate Lever case set from Pipe shaft complete. (Fig. 15)
(7C) Remove the following parts from Pipe shaft complete.
• Hanger set • Spacer • Shaft
Fig. 11
Fig. 13 Fig. 14 Fig. 15
Fig. 12
DISASSEMBLING
M5x30 Hex socket
head screw (4 pcs.)
Handle clamp 28
Shaft
Shaft pipe
complete
Wire clamp (2 pcs.)
M5x18 Hex socket head bolt
Pipe housing
Hanger set
Loop handle 28
Pipe clamp
Bike handle section
Shaft pipe
complete
M5x14 Hex socket
head bolt (2 pcs.)
Control lever assembly
Shaft pipe
Shaft pipe complete
M6x25 Hex
socket head bolt

[4] DISASSEMBLY/ASSEMBLY
[4]-3. Shaft pipe complete (cont.)
Repair
P / 2
For 4351UH:
(1A) Insert Buffer rubber into Pipe housing so as to align the two grooves
with the two ribs (Fig. 16) Set the four Buffer rubbers in place of
Pipe housing. (Fig. 17)
(2A) Insert two projections of Clutch case into Buffer rubbers.
Insert two projections of Housing holder into the other Buffer rubbers,
then tighten M5x18 Hex socket head bolt while holding Housing
holder by hand. (Fig. 17)
Note: Make sure that Corrugate tube is put in the groove of Pipe housing.
(Fig. 18)
(3A) Assemble by reversing the disassembly procedure.
For 4350UH and 4350LH:
Assemble by reversing the disassembly procedure.
Fig. 16
Fig. 18
Fig. 17
ASSEMBLING
Ribs of Pipe housing
Projections of Clutch case
Groove of Pipe housing
Grooves of
Buffer rubber
Buffer rubber (4 pcs.) Housing holder
Pipe housing
Corrugate tube

[4] DISASSEMBLY/ASSEMBLY
[4]-4. Gear case assembly
Repair
P / 2
(1) According to the clause of [4]-3, Remove Gear case assembly. (Refer to Figs. 8, 9 and 10)
(2) Remove M8x10 + Hex bolt from the grease inlet of Gear case assembly. (Fig. 19)
(3) Remove Retaining ring R-26 with 1R006. (Fig. 20)
(4) Remove an assembled part of Spiral bevel gear 13*, Ball bearing 6000ZZ, Ball bearing 6000 and Retaining ring S-10
by tapping Gear case assembly with Plastic hammer. (Fig. 21)
Note: If the assembled part cannot be removed, use a heat gun or hair dryer to warm Gear case assembly.
(5) Remove Retaining ring S-10 with 1R291. (Fig. 21)
(6) Receive Ball bearing 6000 with 1R031, then press down the shaft end of Spiral bevel gear 13 using 1R282 with
Arbor press. (Fig. 22) Refer to Fig. 23 for the components.
(7) Remove Retaining ring R-32 with 1R291. (Fig. 24)
(8) Preset Receive washer and 1R033 with M10-17 Hex nut to Cutter shaft complete* as drawn in Fig. 25, and give
the impacts using the plastic hammer. An assembled part of Cutter shaft complete* and Ball bearing 6201LLU is
removed. Refer to Fig. 26 for the components.
(9) Remove Ball bearing 6201LLU with 1R045.
*Neither Spiral bevel gear 13 or Cutter shaft set is supplied individually. It is supplied as a set “Cutter shaft set”.
Fig. 19
DISASSEMBLING
Fig. 21 Fig. 22
Fig. 20
Fig. 25 Fig. 26
Fig. 24
Fig. 23
M8x10
+ Hex bolt
1R031
Arbor press
M8x10
+ Hex bolt
Retaining ring R-26
Retaining
ring R-32
Spiral bevel gear 13*
Ball bearing 6000ZZ
Retaining ring S-10
Receive
washer
Gear case
assembly
M10-17
Hex nut
1R033
Retaining ring R-26
It was removed by the previous step (3).
Retaining ring R-32
It was removed by the previous step (7).
Ball bearing 6201LLU Ball bearing 629ZZ
Cutter shaft complete*
O ring 32
Ball bearing 6000
Assembled part
Retaining ring S-10
Ball bearing
6000
Ball bearing
6000ZZ
1R282
Spiral bevel
gear 13*

[4] DISASSEMBLY/ASSEMBLY
[4]-4. Gear case assembly (cont.)
Repair
P / 2
Assemble by reversing the disassembly procedure.
Note:
• Make sure that O ring 32 is put into the inner groove of
Gear case assembly in advance.
• When mounting Cutter shaft complete into Gear case
assembly, press-fit them together using arbor press and
1R028 as shown in Fig. 27.
ASSEMBLING
Fig. 27
1R028
Gear case assembly
Ball bearing
6000DDU
The components of
Cutter shaft complete
[4]-5. Clutch shoe
Warning: Remove Spark plug cap from Spark plug to prevent accidental engine starting.
Note: Clutch can be easily removed with a cordless impact driver without locking Piston, because it is locked in a position
due to the compressed air resistance in Cylinder.
Therefore, do not remove Spark plug, or the air in Cylinder cannot be compressed.
(1) Remove two Clutch shoes and Tension springs 5 by loosening each M8 Shoulder hex bolt counterclockwise. (Fig. 28)
(2) Remove Clutch base by turning the hex portion counterclockwise. (Fig. 29)
(1) Set Clutch base in place by turning the hex portion clockwise.
(2) Set two Clutch shoes and Tension springs 5 in place by tightening each M8 Shoulder hex bolt clockwise; first by hand,
then with a cordless impact driver*
*This is because the M8 Shoulder hex bolt is a shoulder bolt. Therefore, tighten by hand until the shoulder of the shaft portion contacts the upper end
surface of Clutch shoe, then tighten fully with a cordless impact driver. (Fig. 30)
Note:
• Face the arrow marks on Clutch shoes toward the upper side. (Fig. 31)
• Put Clutch shoe between Wave washer 10 and Flat washer 8, then tighten M8 Shoulder hex bolt.
Refer to Figs. 30 and 31.
DISASSEMBLING
Fig. 30 Fig. 31
ASSEMBLING
Fig. 28 Fig. 29
Clutch shoe (2 pcs.)
M8 Shoulder hex bolt
(2 pcs.)
Hex portion of
Clutch base
Tension spring 5 (2 pcs.)
Flat washer 8
Flat washer 8
(2 pcs.)
Wave washer 10 (2 pcs.)
M8 Shoulder hex bolt (2 pcs.)
M8 Shoulder hex bolt Clutch base
Clutch base
Wave washer 10
Clutch shoe
Arrow marks on
Clutch shoes
(2 pcs.)
shoulder
shaft portion

[4] DISASSEMBLY/ASSEMBLY
[4]-6. Clutch drum
Repair
P / 2
For 4351UH: Refer to Parts breakdown in Fig. 35.
(1A) Remove four M6x20 Hex socket head bolts, then separate Clutch case from Engine. (Fig. 33)
(2A) Remove Retaining ring (INT) R-42 in Clutch case with 1R006. (Fig. 33)
(3A) Put 1R247 on Clutch drum in Clutch case, press down Clutch drum using Arbor press. (Fig. 34)
Note: If it is difficult to remove Clutch drum from Clutch case, warm Clutch case with a heat gun.
(4A) Remove Retaining ring (EXT) WR-20 from Clutch drum with 1R004.
(5A) Remove Ball bearing 6004LLU from Clutch drum with 1R045.
For 4350UH and 4350LH: Refer to Parts breakdown in Fig. 39.
(1B) Remove four M6x20 Hex socket head bolts, then separate Clutch case from Engine. (Fig. 36)
(2B) Remove three M5x20 Hex socket head bolts, then separate Pipe retainer from Clutch case. (Fig. 36)
(3B) Remove Retaining ring R-35 in Clutch case with 1R006. (Fig. 37)
(3B) Put 1R247 on Clutch drum in Clutch case, press down Clutch drum using Arbor press. (Fig. 38)
Note: If it is difficult to remove Clutch drum from Clutch case, warm Clutch case with a heat gun.
(4B) Remove Retaining ring S-17 from Clutch drum with 1R004.
(5B) Remove Ball bearing 6003LLU from Clutch drum with 1R045.
Fig. 35Fig. 34Fig. 32
Fig. 33
DISASSEMBLING
Clutch case
Clutch
case
Ball bearing
6004LLU
Inside view of
Clutch case
Fig. 39Fig. 38Fig. 36
Fig. 37
Inside view of
Clutch case
Pipe retainer Clutch case
Clutch drum
Clutch drum
1R247
Arbor
press
Engine
Clutch case
Holes for
access to
Retaining ring
(INT) WR-42
Holes for
access to
Retaining ring R-35
Retaining ring
(EXT) WR-20
Retaining ring
(INT) WR-42
Clutch drum
Clutch drum
Retaining ring
R-35
Ball bearing
6003LLU
Spacer
Retaining ring
S-17
Clutch drum
Clutch
case
1R247
Arbor
press Clutch case
Clutch case
M6x20 Hex
socket head screw
(4 pcs.)
M6x20 Hex socket head
screw (4 pcs.)
M5x20 Hex
socket head
screw (3 pcs.)
Clutch case
Clutch drum

[4] DISASSEMBLY/ASSEMBLY
[4]-6. Clutch drum (cont.)
Repair
P 1/ 2
For 4351UH:
(1) Press-fit Ball bearing 6004LLU to Clutch drum with 1R031 in Fig. 40.
Note: Put Retaining ring (INT) R-42 between Ball bearing 6004LLU and Clutch drum in advance.
(2) Set Retaining ring (EXT) WR-20 in the groove on Clutch drum.
(3) Put Clutch case on the table of Arbor press horizontally without tilt, and press-fit Clutch drum into Clutch case with
1R286. (Fig. 41)
(4) Set Retaining ring (INT) R-42 to the inner groove of Clutch case.
(5) Assemble by reversing the disassembly procedure.
For 4350LH and 4350UH:
(1) Press-fit Ball bearing 6003LLU to Clutch drum with 1R031 in Fig. 42.
Note: Put Retaining ring R-35 between Ball bearing 6003LLU and Clutch drum in advance.
(2) Set Retaining ring S-17 in the groove on Clutch drum.
(3) Put Clutch case on the table of Arbor press horizontally without tilt, and press-fit Spacer and Clutch drum into
Clutch case with 1R286. (Fig. 43)
(4) Set Retaining ring R-35 to the inner groove of Clutch case.
(5) Assemble by reversing the disassembly procedure.
Fig. 40
Fig. 43Fig. 42
Fig. 41
ASSEMBLING
Clutch drum
Arbor press
Retaining ring (INT)
R-42
Ball bearing 6004LLU
Clutch case
Spacer
(Refer to Fig. 39 of
the previous page.)
Clutch case
1R031
Clutch drum
Retaining ring R-35
Ball bearing 6003LLU
1R031
Arbor press
1R286
1R286

[4] DISASSEMBLY/ASSEMBLY
[4]-8. Ignition system
Repair
P 1/ 2
(1) Remove Plug cap from Spark plug, then check the continuity between Plug cap spring and the ground (earth) terminal
of Ignition coil with a circuit tester. If there is normal continuity, the resistance value will be 2.0kΩ±0.5kΩ. (Fig. 44)
(2) If there is no or intermittent continuity, check the continuity between Ignition cable and Plug cap spring by following
the procedure described below.
1. Apply spray lubricant in Plug cap, then pull out Plug cap spring together with Ignition cable from Plug cap using
small pliers. (Fig. 45)
2. Check if Plug cap spring is properly connected to Ignition cable. If not, connect them properly.
Also check Plug cap for any crack. If Plug cap is cracked, replace it with a new one.
3. Insert Plug cap spring in the center of Ignition cable. Then using small pliers, put them back into Plug cap while
taking care not to disconnect Plug cap spring from Ignition cable.
4. Make sure that Plug cap spring is firmly connected to Ignition cable by doing the same as you did in step (1) with
a circuit tester.
Note: Poor continuity between Plug spring cap and Ignition cable will result in no or weak spark.
Fig. 44
CHECKING PLUG CAP
CHECKING SPARK PLUG
Plug cap spring
Small pliers
Ignition coil
Fig. 45
Plug cap
Circuit tester
Primary wire of
Ignition coil
Plug cap spring
(1) Remove Plug cap from Spark plug, then Spark plug from Cylinder with the supplied socket wrench.
Note: If the electrodes of Spark plug are wet, wipe them with a rag then dry them with an air blower.
(2) Using a wire brush, carefully clean up carbon deposits (if any) from the electrodes and the ceramic insulator
around the center electrode.
(3) Adjust the electrode gap to 0.7 to 0.8mm by carefully bending the side electrode.
Use Feeler gauge set (1R366) to check the gap width:
between the center electrode and the side electrode, insert 0.8mm leaf
of Feeler gauge set. (Fig. 45)
(4) Install another Spark plug into spark plug hole to prevent air/fuel
mixture from leaking outside of engine.
(5) Connect the removed Spark plug with Plug cap, then ground the threads
of Spark plug to a proper metal part of the engine.
(6) With Stop switch on, pull Recoil starter knob gently and check for spark.
Note: • It is hard to see the spark in a bright location. Therefore, be sure to
do the check in a shady but well-ventilated place.
• Sparks do not happen at without exceeding 500 rpm.
(7) If spark is not produced, replace Spark plug with a new one,
then check for spark by following the procedure (1) to (6) once again.
WARNING !!
•When a spark is produced, high-voltage current is delivered from Ignition coil to Spark plug.
It is, therefore, very dangerous to pull Recoil starter knob with your hand on Ignition cable.
Be sure to keep your hands off from Ignition cable when checking for spark.
•Fuel is extremely flammable and fuel vapors are explosive.
Therefore, clean up spilled fuel before starting to check for spark.
Also, be careful not to do the check near Carburetor.
Fig. 46
Electrode gap
must be
0.7 to 0.8mm.
side electrode
center electrode

[4] DISASSEMBLY/ASSEMBLY
[4]-7. Ignition system (cont.)
Repair
P 1/ 2
(1) Before removing Ignition coil, separate Cylinder cover
from Engine, and pull out Primary wire from Ignition coil
in advance. (Fig. 47)
(2) Remove two M4x20 Hex socket head bolts and Ignition coil
from Engine. (Fig. 47)
Note: Be careful to the torque to loosen the bolts because
adhesive is applied on the threads under our quality
control.
Once removing their bolts, do not fail to apply adhesive
to the threads.
(1) Insert 0.3mm leaf of 1R366 between Ignition coil and
the magnet of Flywheel. (Fig. 48)
Ignition coil will be attracted to the magnet through 1R366.
Then, without removing 1R366, fasten Ignition coil to
Engine with two M4x20 Socket head bolts. (Fig. 47)
(2) Remove 1R366. Then make sure that Flywheel does not
touch Ignition coil by turning it by hand.
Fig. 47
Fig. 48
REMOVING IGNITION COIL
MOUNTING IGNITION COIL
Spacer (2 pcs.)
M4x20 Hex socket
head bolt (2 pcs.)
Ignition coil
Flywheel
Ignition coil
Female terminal of
Primary wire
0.3mm thick leaf
of 1R366
Fig. 49
Fig. 50
Fig. 51
DISASSEMBLING
ASSEMBLING
M8 Collared
Hex nut
(1) Turn M8 Collared Hex nut in the center of Flywheel counterclockwise
using a cordless impact driver. (Fig. 49)
(2) Mount 1R364 on Flywheel, then screw two M5 bolts of 1R364 into
Flywheel as drawn in Fig. 50.
Flywheel can now be removed from Crankshaft complete by turning
the center bolt of 1R364 clockwise using a screwdriver or the like.
Important: Screw two M5 bolts evenly.
(1) Wipe off grease and oil from Crankshaft complete.
(2) Aligning the key way of Crankshaft complete with Woodruff key 3 on
Flywheel, install Flywheel onto Crankshaft complete. (Fig. 51)
(3) Screw M8 Collared Hex nut to Crankshaft complete by turning it clockwise
by hand.
(4) Tighten M8 Collared Hex nut firmly using an impact driver.
Warning: Remove Spark plug cap from Spark plug to prevent accidental
engine starting.
Note: Flywheel can be easily removed with a cordless impact driver without
using any locking tool, because Piston is locked in a position due to
the compressed air resistance in Cylinder.
Therefore, do not remove Spark plug, or the air in Cylinder cannot be
compressed.
1R364
Woodruff key 3 on
Crankshaft complete
Keyway in
the hole of
Flywheel
M5 bolt
of 1R364
(2 pcs.)
[4]-8. Flywheel

[4] DISASSEMBLY/ASSEMBLY
[4]-9. Recoil starter
Repair
P 1/ 2
(1) Remove Starter cover assembly by loosening
four M5x20 Hex socket head bolts. (Fig. 52)
(2) Pull Starter rope out of Starter cover assembly
approximately one winding long.
Then hook Starter rope on the U-shaped notch of
Reel, and then turn Reel clockwise until Spiral
spring is unwound. (Fig. 53)
Note: Be careful with Reel because it will turn very
fast.
(3) Remove Reel from Starter cover by loosening
5x10 Tapping screw.
Note: Be careful with Spiral spring that can suddenly
pop out of Starter cover.
(4) Unite the knot of Starter rope to remove the rope
from Reel.
Fig. 52 Fig. 53
DISASSEMBLING
ASSEMBLING
M5x20 Hex socket
head bolt
(4 pcs.)
Starter cover assembly Reverse side of
Starter cover assembly
Reel viewed from Starter cover side
Spring hook
of Reel
U-shaped
notch of Reel
Starter rope
Starter rope
Fig. 55
Fig. 56 Fig. 57
Fig. 54
(1) If Spiral spring has popped out of Reel, put it back in place; hook the outer end of Spiral spring onto the spring hook
of Reel first, then by winding Spiral spring counterclockwise towards the center of Reel. (Fig. 54)
(2) Apply a little amount of Makita grease N No.2 to the whole surface of Spiral spring.
(3) Put a new Starter rope through Starter cover.
Then tie one end to Starter knob and the other to Reel by making
a knot. (Fig. 55)
(4) Make sure that the inner end of Spiral spring is positioned close to
the shaft portion of Starter cover for the step (6). Then put Reel in
Starter cover.
(5) Wind Starter rope around Reel two or three times.
(6) While turning Reel counterclockwise, mount it in Starter cover.
The inner end of Spiral spring will be engaged with the spring hook
of Shaft portion in Starter cover by the counterclockwise rotation of
Reel. (Figs. 54 and 55)
Note: You do not need force to mount Reel in place.
(7) Fasten Reel to the shaft portion of Starter cover with
M6x20 Set screw. (Fig. 56)
Note: Reel is not properly set in place if the rotation of
Reel is slow after the screw is fastened.
In this case, repeat steps (5) and (6) until normal
rotation of Reel is obtained.
(7) Hook Starter rope on the U-shaped notch of Reel.
Then, while pulling Starter rope, turn Reel counter-
clockwise. (Fig. 57)
Release Starter rope from the U-shaped notch and
Starter rope will be wound around Reel due to the
rotational force of Spiral spring. Repeat this operation
until the slack is completely removed from Starter rope. about
10mm
about
10mm
Starter rope
Starter rope
Reel
Spring hook of Shaft portion
in Starter cover
Inner end of
Spiral spring
Outer end of
Spiral spring
Reel M6x20 Set screw
Starter cover U-shaped notch of Reel

[4] DISASSEMBLY/ASSEMBLY
[4]-10. Carburetor section
Repair
P 1/ 2
(1) Press down the tab of Cleaner plate assembly gently and separate
Air cleaner cover from Cleaner plate assembly by loosening
M5x20 Hex socket button head screw. (Fig. 1 of [4]-2.)
(2) Remove Air cleaner element. (Fig. 58)
(3) Remove two M5x60 Hex socket head bolts that fasten
Carburetor assembly and Cleaner plate assembly to Insulator
complete. (Fig. 59)
Note: Remove the bolts completely, or Carburetor cannot be
removed from Insulator complete.
(4) Remove three tubes from Carburetor assembly, then separate
Carburetor assembly from Engine.
(1) Remove four Pan head screws, then separate Metering cover, Metering diaphragm and Metering diaphragm gasket
from Carburetor. (Fig. 60)
Note: If Metering diaphragm gasket is sticking on the adjacent part, remove it with care because it is easily broken.
(2) Check Metering diaphragm for shrinkage, hardening or breakage due to aged deterioration. If any, replace it with
a new one.
(3) The inner parts of Pump body assembly can be removed by separating the pan head screw designated in Fig. 61.
(4) Before mounting the inner parts of Pump body assembly in place, make sure that the tip of Inlet needle is neither
worn nor deformed. (Fig. 62)
Note: The inner parts are not available individually. If you need any of the inner parts, order Pump body assembly.
(5) When mounting Control lever, make sure that the upper end of Spring is firmly held in place under the projection of
Control lever. (Fig. 63)
(6) Remove the pan head screw of Pump cover. (Fig. 64)
(7) Make sure that Inlet screen is not clogged, then set it back in place. (Fig. 65)
(8) Spray Carburetor cleaner in all the fuel lines of Carburetor, then after several minutes, wash out dirt and debris with
clean gasoline.
Fig. 60 Fig. 61
Fig. 65
Fig. 63
Fig. 64
Fig. 58 Fig. 59
DISASSEMBLING
DISASSEMBLING/ CLEANING CARBURETOR
Air cleaner element M5x60 Hex socket
head bolt (2 pcs.)
Pan head screw (4 pcs.)
Pan head screwPump cover
Carburetor Pump body assembly
Fig. 62
An Inlet needle with
worn tip can cause
a pressure leak.
with good tip with worn tip Correct assembling
of the inner parts of
Pump body assembly
Wrong examples
Metering diaphragm
Inlet needle
Spring
Control lever
Inlet screen
Carburetor body
Debris in valve seat can
cause a pressure leak.
The upper end of Spring
is out of place.
Control lever is not parallel
to Pump body assembly.
Pan head screw Pin
Inlet needle
Control lever
Spring
Inner parts of Pump body assembly

[4] DISASSEMBLY/ASSEMBLY
[4]-10. Carburetor section (cont.)
Repair
P / 2
Fig. 67
Fig. 69
Fig. 68
Tube 3-250 (black)*
between Carburetor
and Fuel tank
*The component of
Tube complete
Tube 3-120 (blue)
between Primer pump
and Carburetor
Tube 3-35 between Carburetor
and Insulator complete
ASSEMBLING CARBURETOR
Assemble by reversing the disassembly procedure.
Note: Make sure that the assembling direction of each part is correct.
VACUUM LEAK TEST OF CARBURETOR
Connect 1R127 with the fuel inlet of Carburetor, then increase the testing
pressure up to 0.05Mpa. The pressure will stay the same about 10 seconds
if there is no vacuum leak. (Fig. 66)
MOUNTING CARBURETOR
(1) Fasten the following parts to Cylinder block assembly with two M5x60 Pan head screws. (Fig. 67)
Carburetor gasket (2 pcs: small and large) , Carburetor, Cleaner plate assembly, Insulator complete
(2) Connect three Tubes to Carburetor as drawn in Fig. 68.
Then connect Tube 5-160 and Pipe to Cleaner plate assembly as drawn in Fig. 69.
(3) Mount Air cleaner element onto Cleaner plate assembly.
(4) Mount Air cleaner cover complete onto Air cleaner plate, then secure with M5x20 Hex socket head bolt. (Fig. 1 of [4]-2.)
Note: Be sure to fit the tab of Cleaner plate assembly into the slot of Cleaner cover assembly.
Fig. 66
1R127
Carburetor
Tube 5-160 (black) for Rocker cover outer
and Cleaner plate assembly
Clamp on Insulator completeClamp on
Rocker cover outer
Fuel tank
Primer pump
CarburetorInsulator complete
(Spiral tube 6-100 to
protect Tube 3-120)
Pipe for Cleaner plate assembly and the nipple of Cylinder block assembly
Cleaner plate assembly
Cleaner plate
assembly
(Corrugate tube)
Tube 5-160 and Pipe are connected as follows:
Tube 5-160
(black)
Cylinder
block
assembly
Pipe
Carburetor
gasket (small)
Carburetor
Carburetor gasket (large)
behind Carburetor
Cleaner plate
assembly
M5x70 Pan head
screw (2 pcs.)
Carburetor
gasket (small)
Carburetor
gasket (large)

Repair
P / 2
Fig. 67
Fig. 68 Fig. 69
Fig. 66
[4] DISASSEMBLY/ ASSEMBLY
[4]-11. Stop switch section
CHECKING STOP SWITCH
FUEL TUBE ROUTING
Check the continuity between the bullet terminals on the two lead wires
extending from Control lever with a circuit tester. (Fig. 66)
If Stop switch functions properly, there will be no continuity with
the switch ON and there will be continuity with the switch OFF.
Set Tube complete* in place as shown in Fig. 67.
• Connect Tube 3-260 to Carburetor and Gasoline filter with Hose clamp.
• Connect Tube 3-150 to the long pipe of Primer pump.
• Connect Tube 3-120 to the short pipe of Primer pump.
Also refer to Fig. 68.
(3) Put Coil spring 8 and Clamp on Tube 3-150. (Fig. 67)
(4) Route Tube 3-150 as drawn in Fig. 68.
Route Tube 3-120 between Tube 3-150 and Cleaner plate assembly. (Fig. 69)
Tube 3-260 (black)
Holders of
Cleaner plate assembly
Fuel tank
Breather (to intake air into Tank)
Tube 3-150 (blue)
(to intake air into Tank)
[4]-12. Fuel tube section
Tube complete
Breather
long pipe of
Primer pump
short pipe of Primer pump
to connect Tube 3-120
(Refer to Figs. 68 and 69.)
Hose clamp
Nipple of Carburetor
Tube 3-120
(blue)
Tube 3-120
(blue)
Tube 3-150 (blue)
Pipe Breather
Tube 3-150
(blue)
Spiral tube
6-100
Spiral tube 6-80
Tube 3-260
(black)
Fuel tank
(to Carburetor)
Gasoline filter
Grommet
Tube
3-150
(blue)
Tube 3-260
(black)
Coil
spring 8
Clamp

[4] DISASSEMBLY/ASSEMBLY
[4]-13. Engine block
Repair
P / 2
(1) It is highly recommended to drain the oil system of Engine block before starting disassembling
because the oil remaining there will drip out to delay your operation.
(2) From the engine section, remove the following parts):
Ignition coil, Flywheel complete, Rocker cover inner, Rocker cover outer, Rocker arm assembly (2 pcs),
Rod 2.5 (2 pcs), Cam lifter (2 pcs), Cam gear assembly, Insulator complete, Cleaner plate assembly, Carburetor,
Spark plug, Exhaust muffler.
(3) Remove the assembly of Cylinder head and Cylinder block. (Fig. 70)
(4) Remove Clip (2 pcs. in total) from each end of Piston pin with a pointed tool such as an awl as shown in Fig. 71.
Note: •Be careful with Clip because it can pop out unexpectedly during removal operation.
•Do not use removed Clip. Be sure to replace it with new one.
(5) Remove Piston pin with 1R171 or the like as shown in Fig. 72.
(6) Remove Piston from Crankshaft complete, then separate Top ring, Second ring and Oil ring from Piston.
Note: Mark on one of Top or Second ring to distinguish the original position for reassembling.
Fig. 70 Fig. 71
Fig. 72
DISASSEMBLING
Crank case
Piston
Piston
Awl
Piston pin
Clip
Crank shaft
complete
Cylinder head
Cylinder block
1R171

[4] DISASSEMBLY/ASSEMBLY
[4]-13. Engine block (cont.)
Repair
P 18/ 22
ASSEMBLING
(1) Connect Piston with Crank shaft complete by inserting Piston pin into place; there is no front/back to Piston.
Note: Be sure to apply a little amount of Makita grease N No.2 to Needle roller bearing.
(2) Secure Piston pin by mounting Clip onto each end of Piston pin. Any setting direction is allowed.
(3) Install Oil ring in the grooves of Piston; Side rail first, Spacer next, then the other Side rail.
Important: Be sure to fit the three rings with the ring gaps at 120 degrees to one another as shown in the left of Fig. 73.
(4) Install Second ring first then Top ring in the groove of Piston.
Important 1: Be sure to fit the two rings with the ring gaps at 180 degrees to each other as shown in the right of Fig. 73.
Important 2: Second ring has a taper face and must be installed with the large diameter facing Oil ring. (Fig. 74)
Distinguishing between Top ring and Second ring & Discriminating the larger diameter of Second ring:
If both of the two rings are new and unused,
•You can distinguish from their appearances; there is a T marking on the right upper end of Second ring as shown in
Fig. 75 while not on the upper end of Top ring.
•You can face the large diameter of Second ring by placing Second ring with the T marking on your right and
with the ring gap near you as shown in Fig. 75.
If both of the two rings are used and the T marking of Second ring is rubbed off, carefully press the side face of
the two rings to the inner wall surface of Cylinder. You will be able to distinguish the two rings or to discriminate
the large diameter of Second ring through the differences in contact feelings that the different side faces make.
Fig. 73
Top ring
Second ring
Fig. 74 Fig. 75
Fig. 76
Top ring, with barrel face
Second ring, with taper face
Side rail
Side rail
Spacer Oil ring
ring gap
ring gap
Note: Makita genuine second ring
has T marking on the right
upper end if it is not worn out.
Face the T marking toward
upward for assembly.
Second ring
T marking
Crank case viewed
from the upper side
Gray colored portions:
where the adhesive should
be applied
Do not apply the adhesive
to the designated area.
Oil ring ring gap
ring gap
ring gap
Side rail
Side rail
Spacer
(5) Apply 4-cycle engine oil to the following portions:
Oil ring, Needle roller bearing that holds Piston pin,
Needle roller bearing of Crank shaft complete.
(6) Remove oil/grease from the mating surface of
Cylinder block and Crank case.
Then apply ThreeBond 1215/ 1216 carefully to
the mating surface of Crank case as shown in Fig. 76.
Note: Do not apply the adhesive to the area
designated by the enlarged view.
Apply 4-cycle engine oil to the sliding surface of
Piston section and Cylinder block assembly, and then
while compressing Piston rings, mount Cylinder block
onto Crank case.
(7) Tighten eight M6x25 Hex socket head bolts in
a crisscross pattern.
T

[4] DISASSEMBLY/ASSEMBLY
[4]-13. Engine block (cont.)
Repair
P 19/ 22
(8) Adjust Valve clearance as follows:
1. Align the marks on the following parts:
• Ignition coil and Flywheel complete (Fig. 77)
• Cam gear assembly and Cylinder block (Fig. 78)
2. Set two Cam lifters and two Rods 2.5 in place, then assemble two Rocker arm
assemblies to them.
Note: The ends of two Rods 2.5 have to be fit into the holes on Rocker arm assemblies
and Cam lifters. (Fig. 79)
3. Assemble Cam gear cover gasket and Cam gear cover to Cylinder block assembly by
tightening four M5x16 Hex socket head bolts firmly.
4. Revolve Flywheel assembly two turns clockwise (Fig. 80) and align the marks on
Flywheel complete and Ignition coil to move Piston to the upper dead point. (Fig. 77)
5. Tighten Hex nuts of Rocker arm assemblies, then loosen Adjusting screws of Rocker arm assembly.
Insert 0.08mm thick leaf of 1R366 into the clearance between Rocker arm and Valve section (Re: Fig. 81), then
adjust the valve clearance.
6. After checking the feeler gauge can be passed through the clearance and the clearance itself is not more than
0.12mm, tighten Hex nuts of Rocker arm assembly securely, and then remove the gauge from the clearance.
Note: While making two Rocker arms close to the center (Fig. 82), adjust the valve clearance with Hex nuts pushing
down by hand slightly (Fig. 83) and check the valve clearance.
After setting Spark plug in place and turning Flywheel left and right to 45 °two or tree times (Fig. 84), retry
checking of the valve clearance.
Fig. 77
Fig. 80
Fig. 83 Fig. 84
Fig. 81 Fig. 82
Fig. 78
Fig. 79
DISASSEMBLING
Mark on Ignition coil
Mark on Flywheel
Mark on
Cam gear assembly
Hole on
Rocker arm
assembly
Rod 2.5
Hole on
Cam lifter
Mark on
Cylinder block
M5 Hex nut (2 pcs.)
1R170
Hex bit
Adjusting screw (2 pcs.)
0.08 mm thick leaf
of 1R366
Rod 2.5
Push down Hex nut of
Rocker arm
Rocker arm (2 pcs.)
Refer to Fig. 81 for
the cross section.
Valve section
Rocker arm

[4] DISASSEMBLY/ASSEMBLY
[4]-13. Engine block (cont.)
Repair
P 20/ 22
Assemble by reversing the disassembly procedure.
(1) Remove two Rocker arm assemblies and Pin 5 from Cylinder block assembly. (Fig. 85)
(2) Push a rag into Cylinder block assembly from the bottom side so as not to fall off Intake valve and Exhaust valve.
The rag works as protection of the inside of Cylinder block assembly.
(3) Remove Cotters, Retainers and Compression springs 11 from Intake valve and Exhaust valve with 1R389 and 1R005.
(Figs. 86 and 87)
Fig. 85
Fig. 86
Fig. 87
ASSEMBLING
DISASSEMBLING
[4]-14. Valve section
Rocker arm assembly
(2 pcs.)
Pin 5
1R005
Cotter
(4 pcs.)
Cotter (4 pcs.)
Retainer (2 pcs.)
Compression spring 11 (2 pcs.)
Exhaust
valve
Intake
valve
1R389