MODEL EH561/EH760 SERVICE MANUAL
. 1 SPECIFICATIONS a. Designation of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . b. Specifications ........................................................... 3 4 . 2 PREPARATIONS a. Disassembly & Reassembly Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 b. Cautions 6 .............................................................. . 3 DISASSEMBLY 81ASSEMBLY PROCEDURES .....................
1 SPECIFICATIONS a.
b. Specifications I Model EH760 EH561 Dimensions (L x W x H) mm 1,041 x 280 x 258 840 x 246 x 225 Mass (with blade cover) kg 5.8 5.8 Volume (fuel tank) cm3 600 Engine displacement cm3 21.7 Cutting length mm Maximum engine performance kw 735 560 0.74 I Maximum blade speed m/s 1 1.88 1 Idling speed l/min I 2,600 Clutch engagement speed l/min Carburetor type type WALBRO WYL Ignition system type Solid ignition system Spark plug type NGK-BMR7A Electrode gap mm 0.
2. PREPARATIONS a. Disassembly and Reassembly Procedures The disassembly and reassembly procedures mentioned below are given as a general rule. These procedures can be added to or omitted according to your operating conditions. II. PREPARATIONS Cleaning Drainage of fuel Disposition of tools I Ill. DISASSEMBLY 1. Machine body 2 Engine Cleaning of parts CHECKUP Checking of parts (Refer to IV. CHECKUP AND ADJUSTMENT) (Refer to V. STANDARD OF ADJUSTMENT) (Refer to X. SETTING OF BRUSH BLADE) 1 1.
b. Cautions 1) Preparations (1) Workbench (2) Disassembly and reassembly kits and gauges (3) Washing bowl (4) Rinse oil (light oil, gasoline, etc.) (5) Oil (mobile oil), grease (6) Adhesive, sealant (7) File, sandpaper (8) Shop cloth 2) Cautions in Disassembly (1) Use standard tools correctly. (2) Handle disassembled parts with care and be sure to clean them. In particular, remove dust or dirt adhering to the mounting surfaces of packings. Bearings in rod are easy to separate.
3.
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a. Removal'of Engine and Machine Body For EH561 1. StarVStop lead wire Remove lead wire connecting rear-handle stop switch with engine. 2. Throttle wire Remove cable holder fixed to rear handle by loosening screw (M4 x 10). Remove throttle wire from throttle lever parts. Cable h o l d e r 3. Engine Remove engine by loosening two bolts (M6 x 15, PW, SW) with fixing case and engine and one bolt (M6 x 40, W, SW) with combine rear handle with case and engine. 4.
For EH760 * 1. StarVStop lead wire Remove lead wire connecting rear-handle stop switch with engine. 2. Throttle wire (For STD) Remove throttle wire form throttle lever. (For CE) Remove throttle wire from carburetor. 3. Left handle Loosening two bolts (M5 x 30)with handle holder. 4. Handle holder Loosen two bolts (M6 x 35, W, SW) with engine. 5. Engine Remove engine by loosening three bolts (M6 x 15, PW, SW) with fixing case and engine. 6.
b. Disassembly 4% Assembly of Machine Body Crank q e a r Drum . \ U p p e r case -Lower ca5 Pinion qear / 1. Drum Lock blade by tightening 3 blade slide screws to the full. Then remove drum by using drum hole. If drum can not be loosened, apply wood chip under blade nearer at engine and remove drum by using drum hole. The screws are right-handed. Turn to the left in loosening. Be careful not to miss collar under drum. 2. Lower case Remove 3 blade-fixing U-nuts first.
3. Rod slide plate, Pinion gear, Felt Loosen 2 screws (M3 x 5) and remove rod slide plate fixed under lower case. Then remove pinion gear from upper case. If it is hard to remove, tap pinion with plastic hammer. Then remove felt. 4. Rod Remove rod on lower-blade side. Before removing rod, apply a small amount of grease to needles and turn rod several times so that they will not separate. Keep in memory rod mounting direction. Apply grease to crank and lower-blade rod shift and mount rod. 5.
c.
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1. Fuel tube Pull fuel tube about 20 - 30 mm out side fuel tank for easy assembly. Assemble fuel tube as shown in the figure. Return fuel tube to within the tank following assembly. (with no bends that might prevent smooth fuel flow) 2. Cylinder cover Keep the muffler gasket and insulator gasket in the correct position when assembling the cylinder cover. Insulator Keep the cover spacer and washer in the correct position when assembling the cylinder cover to the cylinder. 3.
4. Clutch Keep the washer in the correct position when assembling the clutch. 5. Ignition coil Use thickness gauge to assure that the air gap will be 0.3 - 0.4 mm between the ignition coil and flywheel magnet portion when installing the ignition coil. 6. Flywheel Install the socket head bolt onto the crankshaft and tighten them securely. Remove the flywheel with a pulling tool as shown in the figure.
9. Piston When equipping the piston in the crankshaft ass’y, the triangular mark ( A ) on the top of the position should be on the crankshaft key slot side. 10. Piston ring When installing the piston ring on the position, align the knock pin on the piston with the split on the piston ring. Unless they are lined up the cylinder cannot be assembled.
d.
(1) Throttle Valve Controls engine output. (2) Tamper Resistant Plug: Prevents entry of air and foreign matter. (3) Low-Speed Needle: Regulates fuel at idling or slow rpm. (4) Inlet Screen: Filters fuel intake to carburetor. (5) Needle Valve: Controls fuel supply to metering chamber from fuel pump. (6) Fuel Inlet: For fuel intake. (7) Metering Lever Spring: Works together with metering diaphragm to ensure constant pressure in metering chamber.
2) Maintenance PI11MLlI PIIMP -I’I1IMLTl I’UMP W L I I - - 21
A) DISASSEMBLY AND ASSEMBLY PROCEDURE 1) Refer to the disassembly drawing when disassembling or assembling. 2) Be careful not to damage gaskets and the like when assembling 3) Do not attempt to disassemble the throttle valve ass’y or pump body ass’y. 4) When you find during disassembly of the carburetor that the inlet screen is clogged or there is considerable dirt buildup in the carburetor itself, be sure to clean out the fuel tank and replace the fuel tank filter.
3) Adjustment of Carburetor (1) Idle adjusting screw The standard idling rotational speed is 2,500 - 2,700 rpm. Adjust the speed as high as possible so that the blade does not turn. Right : for higher speed (rpm) Left : for lower speed (rpm) (2) Metering lever The metering lever is a very important part. Never tamper with it under normal conditions. Measure as shown below, when checking the height of the metering lever or when measurement is necessary. Standard height: 1.5 0.
4) Troubleshooting METERING SYSTEM Inlet Needle 8 Seat I O I Foreian matter Io I Wom inlet needle valve I Inlet needle valve stuck I Metering Diaphragm I0 I Io I I 0I 0I Diaphragm damage Loose screw on diaDhraam cover Gasket defect I I I Button damage Metering Lever Spring BEl 0 Improper installation 000 Lever set too low Lever set too high 0 0 0 0 Leverdamage CIRCULATION SYSTEM Loose carburetor Io I 00 0 0 0 0 Manifold gasket failure 0 Check valve failure (foreign matter) I 0I PumD d
4. CHECKUP AND ADJUSTMENT a. Daily Checkup and Adjustment 1. Aspect Confirm that there is no damage or wear. 2. Bolts, nuts, damper pin Check bolts and nuts for damage, wear or tightening. Retighten if necessary. 3. Safety cover Check safety cover for damage or loosening. Confirm that the safety cover is mounted in contact with gearcase. 4. Trimmer blade Confirm that Trimmer blade is set correctly. Checkup Trimmer blade for chipping, crack or bend. Replace if necessary. 5.
b. Checkup and Adjustment for Every 30 - 50 Hours (Every 10 Days) 1. Air cleaner Remove cover of air cleaner and cleaner filter inside with gasoline. After wringing, fit it to air cleaner. 2. Spark plug If spark plug is damaged or becomes dirty, clean it well with gasoline or sand it with sandpaper so as to adjust spark gap to 0.6 - 0.7 mm. 0.6- 0.7 mm (0.024- 0.028”) c. Checkup and Adjustment for Every 100 - 200 Hours (Monthly) 1. Cleaning and adjustment of carburetor Clean diaphragm, throttle, etc.
4. STANDARD ADJUSTMENT a. Tightening Torque of Components Main Body 1 1 Tightening Part I Tightening Torque (kg. cm) Grease nipple 35 f 5 Retainer plate 40 !z 50 *5 I Screw (Diam.
b. Standard Adjustment Table I Test Parts I I Air gap Spark plug electrodes gap I I I Standard Size (mm) 0.3 - 0.4 0.6 - 0.7 I I I c. Lubrication Procedure 1) Oil Mobile Oil No. 30. ...................... .Throttle wire 2) Grease Shell Albania No. 3 ....................... .Gear case Always use above oiVgrease or a comparable product. d. Blade sharpening If the edges are rounded and do not cut well any more, find off only the shaded portions.
e. Blade Adjustment The blades will wear with long use. When you find that trimming is not as good as when the blades were new, adjust them as follows. 1. Turn Hexagonal U nut loose. 2. Truss screw in with the driver lightly till it stops turning, and then screw it back one quarter to a half turn. 3.Turn Hexagonal U nut tight, holding Truss screw at the same time with a driver. 4. Lubricate the blades after adjustments above with light oil. 5.
6. TROUBLESHOOTING Y C 2 V e -- c Abnormality inside engine . . . Check 0) .-c c ln a 0 Malfunction of carburetor . . . . Check 0a.0 % .G a). U a C .cn c a v W with coil . I - 0-0 .cL b c v Defective coil ~ a2 2; . . . . . . . . . . . . .Replace - Stop switch is grounded . . . . . Replace ~ - Defective wiring . . . . . . . . . . . Correct 5+g 2% ......... r Defective or damaged spark plug . . - . . . . . . . . . . . . . . . Replace t -maP c m Incorrect spark plug gap . .
, - Inadequatefuel used . . . . . . . . . . . . . . . . . . Use specified fuel - Defective plug (overheated) . . . . . . . . . . . . Replace - -Overheated engine Air ventilation hamperedbecause of cylinder clogged with dust . . . . . . . . . . . . Clean (Inlet of cooling air, fan cover, fan, cylinder fin) - Carbon adhering to combustion chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overhaul, clean - Fuel is too lean . . . . . . . . . . . . . . . . . . . . . .
