REPAIR MANUAL EB7650TH EB7650WH
P 2/ 35 Repair CAUTION: Repair the machine in accordance with “Instruction manual” or “Safety instructions”. Index [1] NECESSARY REPAIRING TOOLS [2] GASKETS AND LUBRICATION [3] DISASSEMBLY/ASSEMBLY [3]-1. Warning [3]-2. Blower Section (Band Completes L and R, Frame and Fan) [3]-3. Throttle Lever Section [3]-4. Engine Section (Rocker Arm, Valve Portion, and Camgear Portion) [3]-5. Air Cleaner Case [3]-6. Carburetor [3]-7. Flywheel [3]-8. Ignition System [3]-9. Crankcase [3]-10.
P 3/ 35 [2] GASKETS AND LUBRICATION ・After removing the gaskets, completely remove any residue. ・When reassembling, replace the gaskets with new ones. ・Use parts cleaner or the like to remove grease from the mating surface of Cylinder and Crankcase and then apply Liquid gasket ThreeBond 1215 as drawn below . ・Apply a small amount of 4-stroke engine oil to each part indicated by in the following diagrams when assembling the parts. ・Apply Makita grease N No.
P 4/ 35 [3] DISASSEMBLY/ASSEMBLY [3]-1. Warning ・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.
P 5/ 35 (2) Loosen three M5x20 Pan head screws and then remove Recoil starter (a). (Fig. 2) (3) Loosen four 5x20 Tapping screws and then remove Engine cover (b). (Fig. 3) Fig. 3 Fig. 2 (b) (a) (4) Remove six M5x16 Hex socket head bolts from the bottom and front of Frame (c). (Fig. 4) Fig. 4 Guard (c) Loosen this screw only when removing Guard. (c) (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.
P 6/ 35 (8) Turn four Compression springs 22 (the upper two are shorter than the lower two) used as vibration damper counterclockwise and then remove them. (Fig. 6) (9) Loosen eleven 5x20 Tapping screws and then remove Rear volute case (i). Remove Elbow (j) together with it. (Fig. 7) Fig. 6 Fig. 7 (i) Lower Upper (j) (10) Loosen the four M6x25 Hex socket head bolts and then remove fan (k). (Fig. 8) Fig.
P 7/ 35 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 case) and the two longer ones should be at the bottom (of Front volute case). (Fig. 6) If Rubber rings at the bottom have been removed, attach them as shown in the photo on the right of Fig. 9 and then screw the springs onto Spring holders. Fig.
P 8/ 35 (5) When fitting Engine cover complete (d), follow 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) Fig. 11 Choke lever Cylinder block assembly Oil guard: Attach before fitting Engine cover complete.
P 9/ 35 (7) When the tubes have been disconnected from Fuel tank during disassembly, connect them as shown in Figs. 13 and 14. Fig. 13 Outside of Fuel Tank Cover the two tubes coming out of Fuel tank, individually, with Spiral tube 6-100, then cover the tube of Breather (e) with the coil spring 8 and then slide Tube guard 20-102 (f) all the way to cover the tubes. Slide (f) all the way to cover the tubes.
P 10/ 35 [3]-3. Throttle 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 head 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 M4x18 Hex socket head bolt and remove Throttle lever B (f). (Fig. 16) Fig. 16 Fig.
P 11/ 35 EB7650WH Disassembly (1) Loosen six 4x18 Tapping screws and then remove Arm cover. (2) Loosen M5x25 Hex socket head bolt and remove Throttle lever (a). (Fig. 17) Fig. 17 (a) Wave washer 20 (3) Remove the head of Control cable (b) from Throttle lever (a), then disconnect the connector (c) of Stop switch wire and then pull out Control cable (b), Lead unit, and Corrugated tube (d). (Fig. 18) Fig. 18 Remove (b). Pull out (d). Disconnect (c).
P 12/ 35 Assembly (1) Fix Lead unit (a) in the lead wire holders of Arm (b) and Arm cover (c). (Fig. 20) Fig. 20 (c) Switch unit (a) (f) (e) (f) Connector (b) (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) Fig. 21 (g) (b) and Flat washer 12 go between (b) and (g).
P 13/ 35 [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 portions. 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. Leave Frame attached. (2) Remove three M6x18 Hex socket head bolts (a) and then remove Muffler gasket (b) and Exhaust port spacer (c). (Fig. 22) Fig.
P 14/ 35 (7) Remove Air cleaner cover and Air cleaner element and then loosen two M5x60 Pan head screws (l) securing Carburetor. (Fig. 51) Do not remove them. Leave them inserted for easier assembling. (Fig. 25) Fig. 25 Leave (l) inserted. Do not remove them. Do not loosen this hex socket head bolt. (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.
P 15/ 35 (11) Move Pusher rods (s) and remove Cylinder head complete (t). (Fig. 28) Fig. 28 (t) (s) (12) Push in Retainer with 1R389 and 1R005 to compress Compression spring 11 (w) and remove Cotter (v) with a bit or the like (u) magnetized with 1R288. (Fig. 29) Fig. 29 (u) 1R389 (v) Retainer 1R005 Cylinder head complete Disassembly of Rocker arm is prohibited. Replace Cylinder head complete entirely. (13) Remove Intake valve (x) and Exhaust valve (y) to replace or clean them. (Fig. 30) Fig.
P 16/ 35 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) Fig.
P 17/ 35 (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 with 1R366. (Fig. 34) When tightening M5x9 Hex socket head screw with (d), hold M5 Hex nut with (e) to prevent it from rotating together with the screw. Fig. 34 1R366 (e) (c) M5 Hex nut (d) M5x9 Hex socket head screw ・Be sure to adjust the clearance after Camgear cover has been attached.
P 18/ 35 [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 cable from Carburetor. (2) Raise (close) Choke lever, then remove two M5x60 Pan head screws (b) and 5x20 Tapping screw (c) from Air cleaner case (a), then disconnect the tubes, and then remove Air cleaner case and Carburetor. (Fig. 39) Fig. 39 (b) (a) (c) (3) The Carburetor can be disassembled as shown in Fig. 40. Fig.
P 19/ 35 (5) Also replace Pump diaphragm (O) if there is any deformation or hardening. (6) Remove Inlet screen (G) while taking care not to deform it and then clean it with carburetor cleaner. (7) Be sure to use carburetor cleaner to clean the main jet portion at the center. ・Do not use air duster because parts such as Check valve may be damaged if they are cleaned with air duster. (8) Replace Metering diaphragm gasket (Q) and Pump gasket (F) if possible when you disassemble Carburetor.
P 20/ 35 (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). Fig. 43 To Rocker arm chamber (b) 1.0 mm or less (c) The gap should be 1.0mm or less. The tubes should not push against (b). (5) Connect the tubes with Hose joint (d) oriented as shown in Fig. 44. Fig.
P 21/ 35 [3]-7. Flywheel Repair Flywheel while the engine is separated from the blower 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 to separate the 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.
P 22/ 35 Disassembly (1) Disconnect the secondary cable 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) Fig. 47 Gap between the electrodes 0.7 to 0.8 mm (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.
P 23/ 35 [3]-9. Crankcase (1) Refer to "[3]-2. Blower Section (Band Completes L and R, Frame and Fan)" (page 4) and then separate the engine section from Frame. (2) Remove the six M6x25 Hex socket head bolts from Front volute case and then detach the engine block. When assembling, tighten the bolts in the order shown in Fig. 50. Fig. 50 1 7 3 4 2 5 6 (3) Remove three M6x18 Hex socket head bolts (a) and then remove Muffler gasket (b) and Exhaust port spacer (c). (Fig. 51) Fig.
P 24/ 35 (6) When replacing Oil seal only, do not disassemble Cylinder block assembly but insert a slotted screwdriver in the lip portion of the inner ring of Oil seal and pull it out. Take care not to damage Cylinder. (7) Remove five M5x25 Socket head bolts (e) from the bottom of the engine section and then remove Oil case (f). (Fig. 53) Fig.
P 25/ 35 (11) The parts that can be replaced are shown in Fig. 56. Fig. 56 (C) (D) (A) (E) (B) (F) (G) (H) (J) (K) (I) (M) (L) (A) Piston (B) Ring spring 12 (C) Top ring (D) Second ring (E) Oil ring (F) Ring spring 12 (G) Piston pin (H) Needle roller bearing (I) Woodruff key 4 (J) Flat washer 41 (K) Oil seal (L) (L) Oil seal 17 (M) Crankshaft complete Assembly (1) Assemble the parts by reversing the disassembly procedure.
P 26/ 35 (3) When assembling Cylinder block and Crankcase, clean off any residue of liquid gasket from the mating surfaces and then remove any grease with parts cleaner. Apply a thin layer of Liquid Gasket ThreeBond 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. Fig.
P 27/ 35 (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) Fig. 61 (k) (l) Control cable Fits in groove Triangular rib (m) (j) (11) Attach Muffler gasket (n) so that it is on the muffler side of the rib (o) of Volute case as shown in Fig. 62. Fig.
P 28/ 35 [3]-10. Completion Inspection Check Points Measure the engine speed with 1R070 while Blower nozzle is attached. Please note that the engine speed will not increase while the nozzle is not attached. (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 2800 to 3000 min-1 at idling and 7000 to 7200 min-1at maximum speed.
P 29/ 35 Circuit diagram Fig.
P 30/ 35 Wiring diagram Fig. D-2 Fix Control cable and Lead unit in the groove of Front volute case. Lead unit Corrugated tube Earth terminal Control cable Hook the earth terminal of Lead unit in the groove of M5-10 Hex nut.
P 31/ 35 Fig. D-3 Switch unit (Stop switch) Fix the lead wires of Switch unit in these lead wire holders. Place Connectors and the slack of lead wires of lead unit in this space. Fix the lead wires of Lead unit in this Lead wire holder. Place the slack of the lead wires of Lead unit in this space.
P 32/ 35 Fix Control cable and Lead unit in the groove of Front volute case. (Fig. D-4 or Fig. D-5) Fig. D-4 Specifications without Line filter (For countries and areas where noise suppression is not required by regulation) Lead unit Control cable Earth terminal Earth terminal Corrugated tube Hook the earth terminal of Lead unit in the groove of M5-10 Hex nut.
P 33/ 35 Fig. D-5 Specifications with Line filter (For countries and areas where noise suppression is required by regulation) Line filter Lead unit Control cable Earth terminal Corrugated tube 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. Earth terminal Hook the earth terminal of Lead unit in the groove of M5-10 Hex nut.
P 34/ 35 Fig. D-6 The lead wire of Switch unit (Stop switch) connected to Switch terminal 1 must be routed between Rib A and the wall of Arm cover. Fix the lead wires of Switch unit (Stop switch) in these lead wire holders. Rib A Switch terminal 1 Switch unit (Stop switch) Place the slack of the lead wires of Lead unit in this space. Fix the lead wires of Switch unit (Stop switch) in this lead wire holder. Rib B Rib C Place Connectors between Rib B and Rib C.
P 35/ 35 Tightening torque specifications Parts to fasten 1 2 3 4 5 6 7 8 9 Engine / Front volute case Fan 250/ Flywheel complete Throttle lever B/ Throttle link Arm/ Throttle lever Arm/ Arm base Handle L/ Handle R Air cleaner cover/ Air cleaner case Recoil/ Engine Lever case L/ Lever case R Parts to fasten 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Crankcase / Cylinder Retainer plate/ Crankcase M8x12 Hex socket bolt (+ Gasket)/ Oil case Oil case/ Crankcase Cylinder head/ Cylinder Flywheel Ign
