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[4] DISASSEMBLY/ASSEMBLY

[4]-8. Engine (cont.)

R

epair

P 1

5

19

DISASSEMBLING

Fig. 54

Note

: Cam gear assembly functions as automatic decompression valve system.

          Valve is slightly open to release the compressed air in Engine at the starting time, before moving fly weight

           by centrifugal effects. It means the insufficient setting of Cam gear assembly will cause engine stall/ extreme

           reaction force at engine running due to too much load by the compressed air. 

(11) Remove Pin 5 that sets Rocker arm assembly in place on Cylinder head complete. (

Fig. 54

)

        Use 1R308 to push out Pin 5.

The distinction of Rocker arm assembly and Push rods (for use of the exhaust system/ intake system) enables you 

shortens the repair process (Gap adjustment between Rocker arms and Retainers is even difficult, however, you can 

adjust it by using 1R366. Refer to 

Fig. 68

.

Important: 

D

isassemble the parts in the room on Cylinder head complete before removing it and 

                    clean the clogged portions in the following steps. You may repair successfully without

                    doing the step (5) and later in the next page. 

(1) Remove Rocker cover complete, then push out Pin 5 on hinge for Rocker arms with 1R308 and remove Rocker arms.

      (Refer to 

Figs. 50

 and 

54

)

(2) Remove Spark plug. Turn Flywheel until Piston comes to the upper dead point by looking through Spark plug hole

      on Cylinder head complete.

 

      Note

: Align the rib as a mark on Flywheel with the rib on Cylinder block as drawn in 

Fig. 55

.

(3) Insert a bent Lead wire #16 into Combustion chamber through Spark plug hole so that Valves do not fall into 

      Combustion chamber. (

Fig. 56

(4) While compressing Compression spring 11 by pushing Retainer with 1R003 attached with 1R389, remove Cotter by 

      a thin bit magnetized by 1R288. 

      Routes in Cylinder head complete, the upper surface on Valves and the room on Cylinder head complete can be clean

      through removal of four Cotters, two Retainers, and two Compression springs 11.

Fig. 55

Fig. 57

Fig. 56

1R389

1R003

Rocker arm assembly

Exhaust 

push-rod

Pin 5

Cylinder head 

complete

Intake

push-rod

Intake

system

Exhaust

system

Rib on Flywheel 

Rib on Cylinder block

Retainer (2 pcs.)

Cotter (4 pcs.)

[viewed from the upper side of the room]

Compression

spring 11 (2 pcs.)

Intake valve

Exhaust valve

Cylinder head complete

Note

: Intake system of Rocker 

          arm has to be close to 

          the hole of Cylinder head

          complete.

the hole of Cylinder head complete

Use Cotter removal 

attachment to push 

Retainer.

Note

: Intake valve has to 

          be close to this hole

          of Cylinder head

          complete.

Summary of Contents for EK7650H

Page 1: ...nk capacity L US oz Fuel consumption L h US oz h Wheel diameter mm Engine Displacement cm cu in Max output kW 4 6 at 5 500 min Max torque N m 4 stroke Specifications EK7651H Model Type Decompression v...

Page 2: ...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 part...

Page 3: ...h the holes of Cylinder head assembly Repair Inner periphery a little Makita grease N No 2 Inner periphery Oil seal 17 Cam lifter R Crankshaft complete Oil seal L P 3 19 109 112 117 Cylinder head comp...

Page 4: ...ate Belt cover and Hood section from the machine Fig 4 5 When Hood section is disassembled 1 Face the blade installation side of Spindle toward the ram of Arbor press 2 Press Spindle out of Cutting de...

Page 5: ...ers 3 Insert Lock shaft into the place of Cutting device then set Sliding disc and Impact plate Push Lock shaft from Belt cover side toward Blade installation side until the top bumps against Impact p...

Page 6: ...e one end through Starter knob and Rope stopper tie the end as drawn in Fig 14 Then cover the top of Starter knob with Cap After passing the other end from the hole of Starter case to Reel tie the end...

Page 7: ...om being rotated Fig 21 3 Turn Flywheel slowly and carefully by hand until the top of 1R372 contacts Piston Note Do not damage Piston 4 Turn the hexagonal portion of Clutch holder counterclockwise wit...

Page 8: ...G FLYWHEEL COMPLETE ASSEMBLING FLYWHEEL COMPLETE Fig 23 Fig 24 Fig 25 M10 Flange nut Flywheel Crankshaft 14mm flats width Socket bit Screwdriver Water pump pliers Woodruff key in key way of Crankshaft...

Page 9: ...to apply the principle of leverage Without being forced to pull put the long noses of Pliers on the edge of Ignition coil and lever up the flag terminal Fig 31 5 Loosen two M5x16 Hexalobular socket he...

Page 10: ...on for compliance with standards 5 Before mounting the inner parts of Pump body assembly in place make sure that the tip of Inlet needle valve is neither worn nor deformed Note The inner parts are not...

Page 11: ...Assemble by reversing the disassembly procedure Be careful to the following points Align the ends of Sponge sleeve 9 and Breather on Tube 3 190 Fig 39 Set Breather in place so that Tube 3 190 is fixe...

Page 12: ...ed it is necessary to remove Engine from Tank complete 1 Remove Hood section Refer to Fig 4 of 4 1 2 Remove Carburetor Refer to 4 5 Refer to Fig 45 and do the following steps 3 4 5 3 Remove three Tube...

Page 13: ...bular socket head bolts that fasten Front handle Tank complete and Engine Fig 46 Engine block can be removed Fig 47 Viewed from Blade installation side Viewed from Starter assembly installation side E...

Page 14: ...complete from Cylinder head complete Fig 50 7 Loosen Hose clamp then remove Suction line from Cylinder head complete Refer to Fig 41 8 Remove Cylinder head complete from Cylinder block then pull out t...

Page 15: ...ith 1R308 and remove Rocker arms Refer to Figs 50 and 54 2 Remove Spark plug Turn Flywheel until Piston comes to the upper dead point by looking through Spark plug hole on Cylinder head complete Note...

Page 16: ...cket head bolts on the bottom of Crank case Fig 58 then remove Crank case from Cylinder block As Liquid gasket makes Cylinder block stick on Crank case insert and twist a slotted screwdriver between t...

Page 17: ...ng by placing Second ring with the red marking on your right and with the ring gap near you as shown in Fig 65 If both of the two rings are used and the white marking of Second ring is rubbed off care...

Page 18: ...rank portion two or three turns check the gap again if the proper gap is obtained tighten the nuts and bolts firmly 12 Lead unit that comes from Stop switch has to be fastened to Cylinder block with 6...

Page 19: ...ted place 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 delive...

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