Makita EB7650TH, EB7650THG, EB7650WH Technical Information

Download

Page 1

Dimensions: mm (“)

Length (L)

332 (13-1/8)

Width 1 (W1)

460 (18-1/8)

Width 2 (W2)

510 (20)

Height (H)

480 (18-7/8)

Model

Specification

4-stroke, single-cy linder, air-cooled

(Makita EH075F1)

Displacement: cm³ (cu.in)

75.6 (4.6)

Fuel

Straight u nleaded g asolin e*1 (E 0 to E10* 2)

Max output: kW (PS)

2.7 (3.7) [at 7,000 minˉ¹]

Max torque: N.m

4.4 [at 5,000 minˉ¹]

at max out put pow er

7,100

at no load

2,800

SAE10W-30,

(4-stroke eng ine oil for automobile)

Carburetor

Diaphragm

Starting system

Easy start (Spring-assisted recoil starter)

Decompression valve

Yes

Spark plug

NGK CMR6A

Primer pump

Yes

Fuel tank capacity: L (US oz )

1.9 (64)

Throttle location

Tube-mounted

Hip-mounted

End nozzle 90-60

89 (200)

End nozzle 90-70

81 (181)

End nozzle 90-60

90 (201)

End nozzle 90-70

81 (182)

End nozzle 90-60

17 (607)

End nozzle 90-70

19 (682)

End nozzle 90-60

17 (611)

End nozzle 90-70

19 (682)

Dry weight: kg (lbs)

10.8 (23.8)

11.0 (24.3)

ECHNICAL INFORMATION

July 2015

OFFICIAL USE

for A SC & Sales Shop

P 1 /35

PRODUCT

Petrol Blower

CONCEPT AND MAIN APPLICA TIONS

Model No.

Description

EB7650TH/ EB7650THG

EB7650WH

EB7650TH/ EB7650THG/ EB7650WH

Models EB7650 TH/ EB7650TH G/ EB7650WH a re Petrol blow ers equip ped wit h

75.6cm³ 4-stroke engine in compliance with strict exhaust emission regulations. These products are ideal for professional use with the following features:

• Higher air speed and larger air volume than our current model BBX7600 for excellent operation effici ency

• 4 damper springs mou nted between t he engine and the b ackpack fram e that reduce vibration on the back of operator even during long hours of operation t o redu ce opera tor st ress an d fatig ue

• Cushioning back padding and shoulder straps well-ventilated for effective sweat evaporati on to provide m ore comf ort Model EB7650TH features tube-mounted throttle while EB7650WH features hip-mounted throttle. Model EB7650THG is E25 compatible.

pecification

EB7650TH/ EB 7650THG EB7650WH

Type

Engine

Speed: minˉ¹ = rpm

Engine oil

Max air speed: m/s*3

Max air volume: m³/min*3

*1 "Straight" means "not mixed with engine oil". *2 EB7650THG: E25 *3 Actual m easured value

tandard equi pment

Oil bottle set*4 Flexible pipe End nozzle 90-60 Long pipe 90 Box wrench 16 Swivel pipe End nozzle 90-70 Driver Hose clamp Flat nozzle 90

*4 W ith engine oil contained for some countries. Note: The standard equipment may vary by country or model variation.

ptional accessories

Short pipe 90 Hip belt set

Long pipe 90

Short pipe 9 0

Long pipe 90

Short pipe 9 0

Class SF or higher of A PI Classification

Page 2

P 2/ 35

Repair

CAUTION: R epair the mach ine in acco rdance with “Ins tructio n manual” or “Safety instructions”.

Index [1] NECESSARY REPAIRING T OOLS P 2 [2] GASKETS AND LUBRICA TION P 3 [3] DISASSEMB LY/ASSEM BLY P 4-28 [3]-1. W arning P 4 [3]-2. Blower Section (Band Completes L and R, Frame and Fan) P 4-9 [3]-3. Throttle Lever Section P 10-12 [3]-4. Engine Section (Rocker Arm, Valve Portion, and Cam gear Portion) P 13-17 [3]-5. Air Cleaner Case P 17 [3]-6. Carburetor P 18-20 [3]-7. Flywheel P 21 [3]-8. Ignition System P 21-22 [3]-9. Crankcase P 23-27 [3]-10. Completion Inspection Che ck Poi nts P 28

[1] NECESSARY REPAIRING T OOLS

Code No. Description Use for

1R005 Retaining ring pliers R T -2N Attaching/removing Cot ter (u sed tog ether w ith 1R 389) 1R070 Tachometer Engin e speed check 1R181 Ignition checker Diagnosis of Ignition coil 1R229 1/4” hex. Shank bit for M5 Loosening/tightening M5 Hex socket head bolts 1R288 Screwdriver magnetizer Attaching/removing Cotter 1R306 Ring spring removing jig Attaching/removing Cotter 1R311 Retaining ring pliers Removing/inserting tubes 1R364 Flywheel puller Removing Flywheel 1R366 Feeler gauge set Adjusting gaps of Spark plug, Rocker arm, an d Ignition coil 1R389 Cotter removal attachment Attaching/removing Cot ter (u sed tog ether w ith 1R 005)

1R402-A Digital tester Diagnosis of Ignition coil

Makita Corporation

Page 3

P 3/ 35

Tips of valves

Outer circumference of Cam lifter

Outer circumference of Push rods

Outer circumference of O-rings 17

Remove grease.

Sliding part s inside the engine

Sealing lips of Oil seals

[2] GASKETS AND LUBRICA TION

・After removing the gasket s, completely remove any residue. ・When reassembling, replace the gaskets with new ones. ・Use parts cleaner or the li ke to rem ove grease from the mating surface of Cylinder and Crankcase and then apply Liqu id gasket

ThreeBond 1215 as drawn below

・Apply a small amount of 4-s troke engine oil to each part in dicated by in the following diagrams when assembling the parts. ・Apply Makita grease N No.2 to the sealing lips of Oil seals and outer circumf erence of O rings 17 and 20 of the anti-icing valve portion

indicated by .

・Apply Makita grease N No.2 to the outer circumferen ce of the O ring of Elbow. ・When attaching Flywheel, use parts clean er or the lik e to remov e the grease from the tapered part.

and 20 of the anti-icing valve p ortion

Makita Corporation

Page 4

P 4/ 35

Fig. 1

Pull out the band as shown above.

Position the buck le vertica lly and then remove it.

Turn t he ce nter of Lock rivet with a Phillips scr ewdriv er to loose n it a

[3] DISASSEMB LY/ASSEM BLY [3]-1. W arning

・There is a risk of a burn injury immediately after the engine is stopped. So wait until the engine has completely cooled

before performing the work.

・Completely remove all fuel from the inside of Fuel tank and Carburetor before performing the work. [No open flames] ・Remove the engine oil before performing the work. ・Perform the work on a solid workbench in a place where dust, dirt, etc. will not enter inside. ・Remember how and where the parts were assem bled when disas sembling th e product and take c are not to m ake a mis take

when assembling the product.

Prepare boxes so that you can store the parts in groups when disassembling the product.

・Handle the removed parts carefully and clean and w ash them properly. ・If a bolt or screw cann ot be loosened, do n ot apply excessive force. Use an impact d river or sim ilar tool. ・Be sure to tighten bolts and screws to the specified tightening torque values. ・After assembling the main parts, turn the engine by hand to check that there is no abnormality or looseness.

[3]-2. Blower Section (Band Completes L and R, Frame and Fan)

Disassembly

(1) Remove Band completes L and R and Hip belt. Remove each of the fixing parts as shown in Fig. 1.

little and then re move it.

Makita Corporation

Page 5

P 5/ 35

Fig. 4

Fig. 2

(a)

Fig. 3

(b)

(c)

Guard

(c)

Loosen this screw only whe n remov ing

Fig. 5

Disconnect (e) from (f ).

(e)

2. Return Throttle

position a nd rem ove

1. Pull Throttle lev er

place with a finger.

(f)

Disconnect (e) from (d) a nd (g).

(d)

For Model EB7650WH,

(g)

Disconnec t the wire f rom the

M5-10 Hex nut

(2) Loosen three M5x20 Pan head screws and then remov e Recoil starter (a). (Fig. 2) (3) Loosen f our 5x20 Tapping screws and then remove Engine cover (b). (Fig. 3)

(4) Remove six M5x16 Hex socket head bolts from th e bottom and front of Frame (c). (Fig. 4)

Guard.

(5) Lift up Fuel tank and disconnect the earth wire of Ignition coil from the brass M5-10 Hex nut beneath Fuel tank. (Left photo of Fig. 5) (6) Disconnect Ignition coil at the bullet te rminals (d) (Center photo of Fig. 5), then disconnect Control cabl e (e) from Carburetor (f)

(Right photo of Fig. 5), and then rem ove the integrated Control cable (e) and Lead unit from Front volut e case (h). In th e case of EB7650WH, remove Con trol ca ble (e) f rom Clip (g). (Center photo of Fig. 5)

earth terminal.

(7) Remove the engine, Volute case and Fuel tank together and then replace Frame (c).

lever to its or iginal

remove (e) from (g).

the wire end.

Makita Corporation

and then hold it in

Page 6

P 6/ 35

(j)

(i)

Fig. 6

(h)

(k)

Upper

Lower

Fig. 7

Fig. 8

(8) Turn four Compression spri ngs 22 (the u pper tw o are sh orter than the lower two) used as vibration damper countercl ockwise and then

remove them. (Fig. 6)

(9) Loosen eleven 5x20 Tapping screws and then remove Rear volute case (i). Rem ove Elbow (j) together with it. (Fig. 7)

(10) Loosen the four M6x25 Hex socket head bolts and then remove fan (k). (Fig. 8)

Makita Corporation

Page 7

P 7/ 35

Protrusion

(b)

Slide Ru bber r ing all the w ay onto each

(a)

(c)

Place the bullet te rminals and

Fig. 9

Fig. 10

Assembly

(1) Tighten the four fan fixing screws in a criss-cross pattern (the order shown in Fig. 8). (2) Screw Compression springs 22 all the way onto Spring holders. The two shorter ones should be at the top (of Rear volute cas e) and the

two longer on es shou ld be at the bottom (of Front volute case). (Fig. 6) If Rubber rings at the bottom h ave been removed, att ach them as shown in the photo on the right of Fig. 9 and then screw the springs onto Spring holders.

Spring hol der w ith the flang ed e nd of the ring facing Front volute case.

(3) Attach Elbow (a) wit h the prot rusi on position ed as s how n in Fig. 9 so that you can rotate Elbow from the front

of the machine and then secure Rear volute case (b) with eleven Tapping screws 5. (Fig. 7)

(4) Attach Frame, then connect Carburetor to Control cable, then connect the bullet terminals and earth wire of

Ignition coil and then secure Guard. (Figs. 4 and 5) Place the bullet terminals in place as shown in Fig. 5 (d) while taking care that it w ill not become pinched

in the engine cover. Place corrugated tube (c) of Model EB7650TH in place as shown in Fig. 10.

line filter in this space, if used.

Makita Corporation

Page 8

P 8/ 35

Left

Right

Twist 90 degrees

Carry out disassembly and assembly

he lever

Insert al ong the gui des

Recoil starter

Three M5x2 0

(d)

Oil guard: Cylinder block

assembly

Choke lever

Four 5x20

Fig. 11

Fig. 12

(5) When fitting Engine cover complete (d), f ollow the instructions described in Fig. 11. Make sure that Carburetor gasket is on the inner

side of the rib inside Engine cover complete and that Plug cover is not pinched.

Align the fixing screw boss positions and then fit the cover and secure it in place with the four screws. (Fig. 3)

Attach before f itting Engine cover complete.

Pan head screws

(6) Secure Band completes L and R with the fixing parts by reversing the disassembly procedure shown in Fig. 1 while taking care not to mix

them up.

with Choke lever raised or t will catch on the engine cover .

Tapping screws

Twist the bands; Band complete R by 90 degrees clockwis e and Band com plete L by 90 degrees counterclo ckwise viewed from the top, and then attach them . (Fig. 12)

Makita Corporation

Page 9

P 9/ 35

Fuel tank

Coil spring 8

(e)

Slide (f) all the way

Spiral tube 6-100

Tube 3-370 (transpare nt bl ue)

Tube 3-370 (black)

Inside of Fuel Tank

Hose clamp

Filter

Tube 3-370 (black)

Tube 3-370

Slide (f) all the way

Fig. 13

Fig. 14

(7) When the tubes have been disconn ected from Fuel tank during disassembly, connect them as shown in Figs. 13 and 14.

Cover the two tubes coming out of Fuel tank, individually, with Spiral tube 6-100, then cover the tube of Breather (e) w ith the coil spring 8 and then slide Tube guard 20-102 (f) all the way to cover the tubes.

to cover the tubes.

Outside of Fuel T ank

to cover the tubes.

(transpare nt bl ue)

Makita Corporation

Page 10

P 10/ 35

(e)

(f) is on the back.

(a)

(b)

(d)

Lever case L

Switch unit

Fig. 15

Fig. 16

[3]-3. Thr ottle Lever Section

EB7650TH

Disassembly

(1) Remove M5x30 thumb screw (a). (Fig. 15) (2) Loosen five 4x18 Tapping screws and then remove Lever case R (b). (Fig. 15) (3) Remove the h ead of Control cable (c) from Throttle lever A (d) and then remove the lever. (Fig. 15) (4) Remove Throttle link (e), disconnect the connector of Switch unit, and then replace Switch unit. (5) Loosen M 4x18 Hex socket head bolt and remove Throttle lever B (f). (Fig. 16)

Assembly

・Attach Throttle link (e) at the position shown in Fig. 16. First secure Throttle lever B (f) with the screw and then turn it counterclockwise

(viewed from the in side) to press the lever of Switch unit and then attach Throttle lever A (d).

Makita Corporation

Page 11

P 11/ 35

W ave washer 20

(a)

Remove (b).

Disconnect (c).

Pull out (d).

(e)

(f)

Tw o rubber sleeves 6

(h)

(g)

T wo tors ion s prings 21

(g)

Fig. 17

Fig. 18

Fig. 19

EB7650WH

Disassembly (1) Loosen six 4x18 Tapping screws and then remove Arm cover. (2) Loosen M 5x25 Hex socket head bolt and remove Throttle lever (a). (Fig. 17)

(3) Remove the h ead of Control cable (b) from Throttle lever (a), then disconnect the connecto r (c) of Stop sw itch wire and then pull out

Cont rol cable (b), Lead unit, and Corrugate d tube (d). (Fig. 18)

(4) Loosen M 6x25 Hex socket head bolt and then rem ove Arm base (e). (5) Disassemble Arm base (e) and Arm base holde r (f) by rem oving on e of two E-4 Stop rings (g) and then pushing out Rod 6 (h) fr om th ere.

(Fig. 19)

Makita Corporation

Page 12

P 12/ 35

(a)

Connector

(e)

Switch unit

(f)

(c)

(b)

(d)

(g)

(b) and Flat washer 12

Fig. 20

Fig. 21

Assembly

(1) Fix Lead unit (a) in the lead wire holders of Arm (b) and Arm cover (c). (Fig. 20)

(2) Be sure to insert Wave washer 20 beneath Throttle lever. (Right photo of Fig. 17) (3) Insert Sleeve 7 (d) into Arm base (g) while aligning the flats of the two parts . (Fig. 21)

go between (b) and (g).

(4) Pass Control cable (e), Lead unit (a), and Corrugated tube through at the position indicated in the right photo of Fig. 18. (5) Insert Arm rubbers (f) (t hey are identical, and the orientation does not matter), and then attach Arm cover (c)

Makita Corporation

Page 13

P 13/ 35

(d)

(e)

(i)

(h)

(j)

(g)

(k)

(f)

(c)

(b)

Muffler

(a) 3 pcs .

Fig. 22

Fig. 23

Fig. 24

[3]-4. Engine Section (Rocker Arm , Valve Portion, and Camgear Portion)

* The blower section does not need to be disassembled when repairing Rocker arm and Camgear p ortions.

Disassembly

(1) Refer to "[3]-2. Blower Section (Band Completes L and R, Frame and Fan)" (page 4), then remove Recoil starter and Engine cover

and then disassemble Camgear portion. Leav e Frame attached.

(2) Remove three M6x18 Hex socket head bolts (a) and then remove Muffler gasket (b) and Exhaust port spacer (c). (Fig. 22)

(3) Refer to "[3]-6. Carburetor" (page 18) and then remove Carburetor. (4) Remove Camgear cover (d). Do not rem ove Pulley (e) or you will have to turn the engine by hand. (Fig. 23) (5) Turn Pulley (e) to align the alignm ent marks (f). Pull out Pin 5 used as cam lifter shaft [part No.256186-0] (g)

and remove Cam lifter L (h) and Cam lif ter R (i). (Fig. 24)

(6) Pull out pin 5 used as Camgear shaft [part No.256200-2] (j) and remove Camgear (k), and then check that the gear teeth and

counterweight portion are not damag ed.

Makita Corporation

Page 14

P 14/ 35

(q)

(r) 5 pcs.

Remove (p) first.

(o)

Do not loose n this hex socke t head bol t.

Leave (l) inserted. Do not remov e them.

1R311

(m)

(n)

Fig. 25

Fig. 26

Fig. 27

(7) Remove Air cleaner cover and Air cleaner element and then loosen two M5x60 Pan head screw s (l) securing Carburetor. (Fig. 51)

Do not remove them. Leave them inserted for easier assembling. (Fig. 25)

(8) Remove Air cleaner case and Carburetor and move them a little out of the way as shown in Fig. 25 and then remove two M5x25 Hex

socket head bolts securing Insulator with 1R229. At this time, do not loosen the lower hex socket head bolt. (Fig. 25)

(9) Remove Plug cap (m) and then disconnect the tw o tubes (n ) wit h 1R31 1. (Fig. 26)

(10) Loosen two M5x30 Hex socket head bolts (o) and rem ove Rocker cover complete (p). Loosen five M6x35 Socket head bolts (r) of

Cylin der head complete (q). (Fig. 27)

Makita Corporation

Page 15

P 15/ 35

(s)

(t)

(v)

1R389

1R005

(u)

Disassembly of Rocker arm is Cy linder he ad

Retainer

(y)

(x)

(v) 4 pcs.

(w) 2 pcs.

Two Retainers

Exhaust port spacer

Fig. 28

Fig. 29

Fig. 30

(11) Move Pusher rods (s) and remove Cylinder head complete (t). (Fig. 28)

(12) Push in Retainer w ith 1R389 an d 1R 005 to c ompres s Compression spring 11 (w) and remove Cotter (v) with a bit or the like (u)

magnetized with 1R288. (Fig. 29)

complete

prohibited. Replace Cylinder head complete entirely.

(13) Remove Intake valve (x) and Exhaust valve (y) to replace or clean them . (Fig. 30)

Makita Corporation

Page 16

P 16/ 35

“N” on the north pole of Flywheel

(a)

Ignition coil

Crankcase

Flywheel

(a)

(b1)

When turning Camgear by

(b2)

Fig. 31

Install so that the convex surface

Fig. 32

Fig. 33

Assembly

(1) Assemble the parts by reversing the disassembly procedure. (2) Rotate Pulley to turn Crankshaft clockwise to align the alignment mark of two lines (a) on Flywheel so that they are parallel with the

surface of Crankcase. “N” on the north pole of Flywheel will be positioned directly below the surface of Crankcase. (Fig. 31)

(3) Align the alignment mark on Camgear (b1) and that of Crankcase (b2), then assemble them and then attach Cam gear cover . (Fig. 32)

hand, rotate Pulley in the direction of the arr ow .

・Please note that the eng ine speed will not increase if even one of t he gear teeth is not aligned.

・Install the gasket so that t he conv ex surface is f acing the eng ine side. (Fig. 33)

・

is facing t he eng ine s ide.

Cross section of gasket

Makita Corporation

Page 17

P 17/ 35

(a)

(b)

(c)

(a)

(d)

(e)

M5 Hex nut

(c)

M5x9 Hex socket head screw

1R366

Fig. 34

Fig. 35

Fig. 36

Fig. 37

Fig. 38

(4) Adjust the clearance between Rocker arm (c) and Valve with a wrench 8 (d) and a hex wrench 2.5 (e) so that it is 0.1 to 0.14 mm when

measured w ith 1R366 . (Fig. 34) When tightening M5x9 Hex sock et head screw with (d), hold M5 He x nut with (e) to prevent it from rotating together with t he screw.

・Be sure to adjust the clearan ce after Camgear cover has been attac hed. If it is adjusted w ith the cover removed, Pin 5 used as Cam

lifter shaft [part No.256186-0] and Pin 5 used as Camgear shaft [part No.256200-2] will not be stable so the clearance w ill chang e when the cover is attached after adjust ment.

(5) Turn Pulley clockwise by hand to rotate Crankshaft twice, check the gap, and then fully tighten. Confirm that a 0.15 mm leaf of the

feeler gauge cannot be inserted.

(6) Apply ThreeBond 1342 or Loctite 243 to three M6x18 Hex socket head bolts for securing Muffler and five M6x35 Socket hea d bolts for

securing Cylinder head complete when you re-tighten them because they are thread locking bolts.

[3]-5. Air Cleaner Case

(1) Pull the nozzle, insert a thin slotted screwdriver at the position shown in Fig. 35, and remov e Separator plate (a). (2) Use the screwdriver in the same way to pull off Separator mesh (b). (Fig. 36) (3) Loosen 3x10 Tapping screw and remove Separator case. (4) Use an awl or similar tool to pull out Check valve (c). (Fig. 37) T a ke care not t o damage it . (5) When installing Separator plate (a), tilt it first and then insert it as shown in Fig. 38.

Makita Corporation

Page 18

P 18/ 35

(I)

(P)

(O)

(F)

(G)

(H)

(Q)

(R)

(C)

(E)

(L)

(D)

(J)

(A)

(B)

(K)

(M)

(N)

(a)

(b)

(c)

Fig. 39

Fig. 40

[3]-6. Carburetor

Disassembly

(1) Refer to "[3]-2. Blower Section (Band Completes L and R, Frame and Fan)" (page 4) and then remove Engine cover complete and

disconnect Control c able fr om Carburetor.

(2) Raise (close) Choke lever, then remove two M5x60 Pan head screws (b) and 5x20 Tapping screw (c) from Ai r cleaner case (a), then

disconnect the tubes, and then remove Air cleaner case and Carburetor. (Fig. 39)

(3) The Carburetor can be disassembled as shown in Fig. 40.

(A) Adjust screw (B) Cable adjust nut M6 (C) Throttle assembly (D) Carburetor (E) Conical c ompre ssion s pring 5-9 (F) Pump gasket (G) Inlet screen (H) Metering diaphragm (I) Metering diaphragm cover (J) Cable bracket (K) M3x10 pan head screw (2 pcs.) (L) Packing ring (M) Main jet (N) O ring (O) Pump diaphr agm (P) Pump body assembly (Q) Metering diaphragm gasket (R) Screw (4 pcs.)

(4) Check the membrane around th e metal part of Metering diaphragm (H) and replace t he diaphragm if there is any deformation or

hardening.

Makita Corporation

Page 19

P 19/ 35

Rotor

Primer pump

Tube 3-370 (transparent),

Tube 3-60 (transparent),

Tube 3-370 (black),

Connect the two black tubes to Air cleaner case (a) and

Branch

Single

(b)

Insert Carburetor gasket

(a)

Insert the two tubes in the

Carburetor

To Rocker arm chamber

To Cylinder s ide

For connecting tubes to Fuel tank,

Fig. 41

Fig. 42

(5) Also replace Pump diaphragm (O) if there is any deformation or hardening. (6) Remove Inlet screen (G) while tak ing care not t o deform it an d then clean it with carburet or cleaner . (7) Be sure to use carburetor cleaner to clean the m ain jet portion at t he center . ・Do not use air duster becau se parts such as Check valve may be damaged if they are cleaned w ith air duster . (8) Replace Metering diaphragm gasket (Q) and Pump gasket (F) if possible when you disassemble Carburetor.

Assembly

(1) Make adjustment of Adjust screw for Cont rol cabl e as shown in Fig. 41.

(2) Check that Rotor contacts the stopper both at idling and full throttle and that the specified rotation speeds (refer to "[3]-10. Completion

Inspection Check Points" [page 28]) are achieved after assembly.

(3) Refer to Fig. 42 for the position to connect each tube to Carburetor.

pass the m thr oug h the cuto ut ho le in Carburetor gasket (large) (b).

(small) here.

refer to assembly procedure 7 of "[3]-2. Blower Sec tion (Ban d Completes L a nd R, Fram e and Fan)" (page 12).

to Fuel tank

right rib. Place the black one beneath the tra nspare nt one. Do not use the left side.

to Carburetor

to Fuel tank

Makita Corporation

Page 20

P 20/ 35

The tubes shoul d

(b)

To Rocker arm chamber

The gap should be

1.0mm or l ess.

(c)

Orientation of (d) viewed f rom t he

Fig. 43

Fig. 44

(4) Use 1R311 to slide the tubes all the way over the nipples (c) until they stop. (Fig. 43)

Make sure that the tubes are not pushing against Carburetor gasket (large) (b)

(5) Connect the tubes with Hose joint (d) oriented as shown in Fig. 44.

not push against (b).

1.0 mm or l ess

45 ﾟ±10 ﾟ

direction of the yellow arrow

Makita Corporation

Page 21

P 21/ 35

(a)

1R364

Temporarily

fasten (b).

Fig. 45

Fig. 46

[3]-7. Flywheel

Repair Flywheel while th e engine is separated from the blow er section.

Disassembly

(1) Refer to "[3]-2. Blower Section (Band Completes L and R, Frame and Fan)" (page 4) and "[3]-9. Crankcase" (page 23) and then

disassemble the blower section t o separate th e engine from the blower section.

(2) Remove M10 Flange nut (right-handed) that is securing Flywheel (a) with a box bit 14 and an impact driver. (Fig. 45) (3) Remove Flywheel with 1R364. Remove it while M10 Flange nut (b) is screwed onto Crankshaft so as to pr event deformati on of the

external (male) thread. Woodruff ke y 4 will come off so take care not to lose it. (Fig. 46)

[3]-8. Ignition System

Use 1R181 f or Ignition coil diagnosis. Refer t o page 24 of "Repair Tool List" for how to use the tool. Disconnect the flag terminal of Stop switch and then, usin g 1R 402, check th e contin uity between earth an d the two places des cri bed bel ow. The polarity of the tester does not matter . (Fig. 48)

Between the earth terminal and Plug cap spring (solid line side) 12 kΩ ±10% Between the earth terminal and the tab terminal for Stop switch (dashed li ne side) 1.0 Ω

Makita Corporation

Page 22

P 22/ 35

While pushing towards (a),

1R402

Disconnec t the flag terminal a nd test the continui ty .

0.3 mm

Fix in t his space. Make sure they will not rise up.

Corrugate d tube

(b)

0.7 to 0.8 mm

Gap between the electrodes

Fig. 47

Fig. 48

Fig. 49

Disassembly

(1) Disconnect the secondary cabl e from Spark plug and then remove Spark plug. (2) Check that the electrode gap is between 0.7 and 0.8 mm and that the electrodes and insulator are not contaminated or damaged. (Fig. 47)

(3) For replacement and adjustment of Ignition coil, refer to "[3]-2. Blower Section (Band Completes L and R, Frame and Fan)" (page

4) and then disassemble the blower section. Repair will be easier if you refer to "[3]-4. Engine Section (Rocker Arm, Valve Portion, and Camgear Portion)" (page 13) and then separate the engine section from the blow er section.

(4) Remove Engine cover and Fuel tank and then remove Ig nition coil.

Assembly

(1) Align the positions of the magnet of Flywheel (a) and the iron c ore of Ignition coil and adjust the air gap with the 0.3 mm leaf of 1R366.

(Fig. 48)

tighten two M4x20 H socket head bolts.

(2) Bend the lead wires of Stop switch an d earth terminal (b) towards the right and then secure them together to Ignition coil. (Fig. 49)

Makita Corporation

Page 23

P 23/ 35

(c)

(b)

Muffler

(a)

(d)

6 4 5

Fig. 50

Fig. 51

Fig. 52

[3]-9. Crankcase

(1) Refer to "[3]-2. Blower Section (Band Completes L and R, Frame and Fan)" (page 4) an d then separate t he engine section from

Frame.

(2) Remove the six M6x25 Hex socket h ead bolts from Front volute case and then detach the engine block.

When assembling, tighten the bolts in the order shown in Fig. 50.

(3) Remove th ree M6x18 Hex socket head bolts (a) and then rem ove Muffler gasket (b) and Exhaust port spacer (c). (Fig. 51)

(4) Loosen t wo M5x25 Hex socket head bolts and on e M5x14 Hex socket head bolt (total of three bolts) an d remove Insulator complete (d).

(Fig. 52) For removing tubes, refer to "[3]-6. Carburetor" (page 18).

(5) Remove Pulley, Rocker cover complete, and Cylinder head complete.

Makita Corporation

Page 24

P 24/ 35

(h)

(g)

(f)

(e)

(l)

(k)

(j)

(i)

Fig. 53

Fig. 54

Fig. 55

(6) When replacing Oil seal only, do n ot di sassem ble Cylinder block assembly but insert a slotted sc rewdriver in the lip portion of the inner

ring of Oil seal and pull it out. T ake car e not to dam age Cylinder.

(7) Remove five M5x25 Socket head bolts (e) from the bottom of the engine section and then remove Oil case (f). (Fig. 53)

(8) Remove four M6x30 Socket head bolts inside the oil cham ber and two M6x30 Socket head bolts outside th e oil cham ber and then

separate Cylinder block (g) and Crankcase (h). (Fig. 54) Crankcase (h) is stuck to Cylinder block (g) with liquid gasket. Insert a slotted screwdriver into the four slots in the mating surface of Cylinder block and Crankcase and turn it to pry them apart. Please not e that insertin g a slotted screwdriver into other than the slots may result in damage

(9) Remove Crankshaft and Piston assembly and then replace Oil seals on the both ends of the shaft, Piston, and Piston rings. (10) Pi ston (i) can be disassembled first by inserting a small slotted screwdriver or sim ilar tool in from the notch (j) shown in Fig. 55,

then by removi ng one of Ring springs 12 (k), and then pushing out Piston pin (l) from the other side.

Makita Corporation

Page 25

P 25/ 35

(C)

(D)

(E)

(A)

(G)

(F)

(L)

(M)

(I)

(B)

(H)

(J)

(K)

(a)

(b)

(c)

(d)

Fig. 56

Fig. 57

(11) The parts that can be replaced are show n in Fig. 56.

(A) Piston (B) Ring spring 12

Top ring (D) Second ring

Woodruff key 4 (J) F lat washer 41

(I) (K) Oil seal (L) (L) Oil seal 17 (M) Crankshaft complete

Assembly

(1) Assemble the parts by reversing the disassembly procedure. (2) Top ring (b) and Second ring (c) of Piston (a) are dif ferent. T op ring (b) has a barrel face profile and has n o top a nd bott om as both sides

are the same. Second ri ng (c) has a taper face profile with larger bottom than top and so orientation matters. A ttach a new second ring so that the white paint (d) mark comes to the side that is on the righ t when viewed from the side surface of Piston (a). (Fig. 57) When inserting Piston into Cylinder:

・The gaps of Top ring (b) and Second ring (c) must be at 180 degrees to each other.

・The gaps of the three parts of Oil ring must be at 120 degree s to one another.

with a barrel face profile

with a taper face profile

Makita Corporation

Page 26

P 26/ 35

(e)

(f)

(i)

(h)

(g)

Fig. 58

Fig. 59

Fig. 60

(3) When assembling Cylinder block and Crankcase, clean of f any residue of liqu id gasket from the mating surfaces and then remov e any

grease with parts cleaner. Apply a thin lay er of Liquid Gasket ThreeB ond 1215 to Crankcase and outer circumference of Oil seals, and apply a thin layer to the parts indicated by solid lines (f) in Fig. 58 while avoiding the grooves indicated by the dashed lines (e) in Fig. 58 so as not to get any in the oil passages.

(4) Make sure that Exhaust port spacer is mounted on the muffler side of Cylinder head complete. Do not forget to mount it in place, and be

careful not to allow it to fall off in assembling Crankcase. (Fig. 51)

(5) Refer to "[3]-4. Engine Section ( Rocker Arm, Valve Portion, and Cam gear Portion)" (page 13) and then assem ble Camgear portion

and attach Camgear cover.

(6) Apply ThreeBond 1 342 or L octite 243 t o the th ree M 6x18 Hex socket head bolts for securing Muffler and the five M6x35 Hex socket

head bolts for securing Cylinder h ead complete when you re-tighten them because they are thread locking bolts.

(7) If Lead valve (g) inside Oil case has been removed, attach it s o that the n otch (h) is facing the oil filler opening. (Fig. 59) (8) Bend Oil tube (i) to the lead v alve side. (Fig. 60)

(9) Attach Front volute case to the engine block and secure with the six M6x25 Hex socket head bolts. (Fig. 50)

Makita Corporation

Page 27

P 27/ 35

(n)

(o)

(k)

Triangular rib

(l)

Fits in groove

(j)

Control cable

(m)

Fig. 61

Fig. 62

(10) When assembling Volute case (j) to Engine section, take care while routing Control cable and high voltage cable (m ) through the

grooves to ensure that Carburetor gasket (k) is in the position shown in Fig. 61 and Insulator complete (l) fits in the groove. (Fig. 61)

(11) Attach Muffler gasket (n) so that it is on the muf fler side of the rib (o) of Volute case as shown in Fig. 62.

(12) Connect Contr ol cabl e to Carburetor and connect the lead wire of Stop switch to Ignition coil. (13) Insert Contr ol cabl e cor rugated t ube an d the bullet terminal in the storage space of Front volute case. For the s pecification with a line

filter, also insert Line filter and any slack wire in the storage space. (Fig. 10)

(14) For the tubes for connecting Fuel tank and Carburetor , attach eac h protector in reference to Fig. 42.

Makita Corporation

Page 28

P 28/ 35

[3]-10. Completion I nspect ion Chec k Point s

Measure the engine speed w ith 1R070 w hile Blower nozzle is attached. Please note that the eng ine speed w ill not increase w hile th e nozzle is not attach ed.

(1) Are the parts, screws, and bolts installed properly? (2) Does a cold engine start within five pulls of Recoil starter? (3) Does the engine speed increase smoothly after idling for about 1 minute?

The engine speed should be 28 00 to 3 000 mi n-1 at idling and 7000 to 7200 min-1at maximum speed.

(4) Check that the rotor cont acts the stop per at both idling and full throttle and that the rotation speeds specified in the previous check point

are achieved after assem bly. (5) Does Stop switch stop the engine properly? (6) Does a warm engine start within three pulls of Recoil starter? (7) Is there no Fuel or oil leak?

Makita Corporation

Page 29

Ignition coil

Switch unit

Earth terminal

Black

White

Black

Lead unit

Ignition coil

Switch unit

Earth terminal

Black

Lead unit

Line filter (if used)

Fig. D-1

ircuit diagram

P 29/ 35

黒

Makita Corporation

Page 30

Fix Control cable and Lead unit in the groove of Front volute case.

Earth termina

Control cable

Lead unit

Corrugated tube

Earth terminal

M5-10 Hex nut

Hook the earth terminal of Lead unit

Fig. D-2

iring diagram

P 30/ 35

in the groove of M5-10 Hex nut.

Makita Corporation

Page 31

P 31/ 35

Fix the lead wires of Switch unit

Switch unit

Place Connectors and the slack of

Fix the lead wires of L ead unit

Place the slack of the l ead wires

Fig. D-3

(Stop switch)

in these lead w ire holders.

lead wires of lead unit in this space.

in this Lead wire holder.

of Lead unit in this space.

Makita Corporation

Page 32

Fix Control cable and Lead unit in the groove of Front volute case. (Fig. D-4 or Fig. D-5)

Specifications without Line filter

by regulation)

Earth terminal

Lead unit

Corrugated tube

Control cable

Earth terminal

M5-10 Hex nut

Hook the earth terminal of Lead unit

Fig. D-4

(For countries and areas w here noise suppr ession is not require d

P 32/ 35

Makita Corporation

in the groove of M5-10 Hex nut.

Page 33

P 33/ 35

Specifications with Line filter

regulation)

Line filter

Earth termina

Lead unit

Corrugated tube

Control cable

Earth terminal

M5-10 Hex nut

Hook the earth terminal of Lead unit

Fig. D-5

(For countries and areas w here noise suppression is required by

Place Line filter and the bullet terminals in this space.

Allow the lead wire of Lead unit to have some slack when routing it here.

in the groove of M5-10 Hex nut.

Makita Corporation

Page 34

P 34/ 35

Switch unit

Fix the lead wires of Switch unit (Stop sw itch)

The lead wire of Switch unit (Stop switch)

Switch terminal 1

Rib A

Fix the lead wires of Place Connectors between

Fix the lead wires of Switch unit

Rib B

Rib C

Place the slack of the l ead wires

Fig. D-6

connected t o Switch terminal 1 must be routed

in these lead wire holders.

between Rib A and the wall of A rm cover .

of Lead unit in this space.

(Stop switch) in this lead wire holder.

Rib B and Rib C.

(Stop switch)

Lead unit (Stop switch) in these lead wire holders.

Makita Corporation

Page 35

Tightening tor que spec ificat ions

Tightening torque

[N・m]

Engine / Front volute case

8.0 - 10.0

M6×25 Hex socket head bolt WR

Fan 250/ Flywheel complete

8.0 - 10.0

M6×25 Hex socket head bolt WR

4 3 Throttle lever B/ Throttle link

1.5 - 1.7

M4×18 Hex socket head bolt

1 4 Arm/ T hrottle lever

0.8 - 1.2

M5×25 Hex socket head bolt WR

1 5 Arm/ Arm base

1.1 - 1.5

M6×25 Hex socket head bolt WR

Handle L/ Handle R

0.9 - 1.4

4×18 Tapping screw

Air cleaner cover/ Air cleaner case

0.9 - 1.2

M5×20 Thumb screw

Recoil/ Engine

2.5 - 4.0

M5×20 Pan head screw

Lever case L/ Lever case R

1.0 - 1.3

4×18 Tapping screw

Tightening torque

[N・m]

Crankcase / Cylin der

10.0 - 12.0

M6×30 Hex socket head bolt

Retainer plate/ Crankcase

2.0 – 3.5

M4×10 Hex socket head bolt SW

M8x12 Hex socket bolt (+ Gasket)/ Oil case

4.0 – 6.0

M8x12 Hex socket bolt t

Oil case/ Crankcase

4.5 – 6.5

M5×25 Hex socket head bolt W, SW

Cylinder he ad/ Cylinder

10.0 – 14.0

M6×35 Hex socket head bolt

5 6 Flywheel

35.0 – 40.0

M10 Nut

Ignition coil/ Crankcase

2.3 – 2.7

M4×20 Hex socket head bolt W, SW

Camgear cover/ Cylinder

4.5 – 6.5

M5×16 Hex socket head bolt WR

Rocker arm/ Adjust screw

4.0 – 5.5

M5 Nut

Rocker cover/ Cylinder head

4.5 – 6.5

M5×30 Hex socket head bolt WR

Spark plug

9.0 – 13.0

M10 Spark pl ug CMR6A

Muffler/ Cylinder head

13.0 – 16.0

M6×18 Hex socket head bolt with thread locker

Insulator / Cyli nder he ad

5.0 – 7.0

M5×25 Hex socket head bolt WR with thread locker

Insulator/ Cylin der

4.5 – 6.0

M5×14 Hex socket head bolt W, SW

Air cleaner case/ Insulator

2.9 – 3.3

M5×60 Pan head screw WR

Air cleaner case/ Insulator

2.2 – 2.7

5x20 Tapping screw

Adjust screw

1.0 – 2.0

M6 Cable adjust nut

Pulley/ Crankshaft

9.0 – 11.0

M8 Pulley (15mm across flats)

Oil cap (+ Gasket)/ Crankcase

0.4 – 0.7

Oil cap

Choke plate/ Choke lever

0.9 – 1.1

4x14 Tapping screw

Air cleaner case/ Anti-icing valve cover

0.9 – 1.1

4x14 Tapping screw

P 35/ 35

Parts to fasten

Fastener pcs

Makita Corporation