Subaru EH36 User Manual

4. GENERAL DESCRIPTION OF ENGINE COMPONENTS 4-1 CYLINDER AND CRANKCASE The cylinder and crankcase is a single piece alu- minum die-casting.

4-4 CONNECTING ROD AND PISTON The connecting rod is an aluminum alloy die-cast- ing and its large and small ends function as bear- ings.

B The intake valve is located on flywheel side of the cylinder head. Hard alloy valve seats are molded in the cylinder head and stellite

4-10 COOLING SYSTEM The large fins on the flywheel provide sufficient cooling air capacity for the inlet and exhaust area and cylinder. The cy

4-13 CARBURETOR The engine is equipped with a horizontal draft car- buretor that has a float controlled fuel system and a fixed main je

4-16 DECOMPRESSION SYSTEM AUTOMATIC DECOMPRESSION SYSTEM An automatic decompression mechanism which opens exhaust valve before the piston reaches

4-17 SECTIONAL VIEW OF ENGINE MUFF P.T.O. MAIN BEARING COVER Fig. 4-16 FLYWHEEL - 13-

FUEL TANK SPARK PLUG I BALANCER SHAFT \ CRANKSHAFT CRANKCASE Fig. 4-17 CAMSHAFT - 14-

5. DISASSEMBLY AND REASSEMBLY 5-1 PREPARATIONS AND SUGGESTIONS 1) When disassembling the engine, memorize the locations of individual parts so t

5-3 DISASSEMBLY PROCEDURES fi Step Fasteners Remarks and procedures Parts to remove Engine oil drain (2) To discharge oil quickly, remove (1) Remove

CONTENTS Section Title Page 1 . SPECIFICATIONS ...

Step Fasteners Remarks and procedures Parts to remove cap nut 2 Air cleaner cover and elements Remove breather pipe from cylinder M6 flange n

Step 4 Parts to remove Fuel tank .r Stop switch M8 BOLT AND WASHER ASSY : Remarks and procedures (1) Close fuel cock. (2) Loosen the nut of fuel

Parts to remove Control box, Diode rectifier, Magnetic switch and Electric starter (Option) Remarks and procedures (1) Disconnect wires and re

Step Fasteners Remarks and procedures Parts to remove 7 Muffler and muffler bracket Be careful not to lose muffler gasket. M8 nut ; 2 pes. M8 x

Parts to remove I Remarks and procedures (1 ) Unhook governor spring from governor lever. Mark the hole on which the governor spring is hooked. g

Step Fasteners Remarks and procedures Parts to remove Recoil starter 10 M6 x 8 ; 4 pcs. (Pulley cover ; type DS and type BS) 11 M6 x 12 ; 5 pcs.. Blo

Step. 12 Parts to remove I Remarks and procedures I Fasteners Ignition coil I (1) Remove spark plug cap from I M6 x 25 ; 2 pcs. spark plug. cra

Step A Fasteners Remarks and procedures Parts to remove 14 M6 x 20 ; 2 pcs. Remove the charge coil. Charge coil (Option) 1 15 1 Cylinder baffle

Parts to remove I Remarks and procedures I Fasteners I r 171 Rocker cover Remove rocker cover and gasket from cylinder head. M6 x 25 ; 4 pcs. I

Step 20 Parts to remove intake and exhaust valves Remarks and procedures (1) Press down spring retainer, take out collet valve, and then re

Section Title Page 7 . AUTOMATIC DECOMPRESSION SYSTEM ... 46 8 . CARBURETOR ...

Step Fasteners Remarks and procedures Parts to remove Main bearing cover M8 Crr)x40;5 pcs. Be careful not to damage the oil seal. 21 M8 (12T)X40 ;

Step Fasteners Parts to remove Remarks and procedures I i? 22 Camshaft and tappets Be careful not to damage camshaft and tappets. Position pi

Step 24 25 Parts to remove Connecting rod and piston Piston and piston pin Remarks and procedures (1 ) Remove connecting rod bolts and (2) Turn

Step 26 Parts to remove Crankshaft Remarks and procedures .Tap lightly on flywheel end of crankshaft to remove from crankcase. I w Fig. 5-22 __1 Fa

B 5-4 REASSEMBLY PROCEDURES 0 PRECAUTIONS FOR REASSEMBLY 1) Clean parts thoroughly before reassembly. Pay most attention to cleanliness of pisto

r I L I I Fig. 5-26 5-4-3 PISTON AND CONNECTING ROD The direction of piston on connecting rod is not specified. Apply oil to the small end of co

(2) Install piston and connecting rod assembly into cylinder. Use a piston ring compressor to hold piston rings. The "FAN" mark of the c

Install balancer shaft to crankcase aligning match- ing mark of balancer gear and crank gear as shown in the illustration. CAUTION : Incorr

D 5-4-7-1 CRANKSHAFT END PLAY (For type D and type B) 1) Measure the depth “Al” (From the mating surface to the inner race of the ball bearing

(2) Lubricate the oil seal and bearing surfaces. Add a light film of oil on main bearing cover face to hold the gasket in place. Place

I EH36 1 MODEL ~~~ ~ ~ EH36B EH36DS EH36D EH36BS I I I Type Air-Cooled, 4-Cycle, Single-Cylinder, Horizontal P.T.O. Shaft, OHV Gasoline Engi

(4) Valve guides should be replaced when valve stem clearance exceeds specifications (See “SERVICE DATA). Draw valve guides out and pre

5-4-10 VALVE CLEARANCE ADJUSTMENT Note: Temporally fit the flywheel in position for easy operation. (1) Position piston at top dead center of com

5-4-1 2 CY LlNDER BAFFLE Install cylinder baffle to cylinder head. M6 x 8 mm flange bolt : 4 pcs. 5-4-13 FLYWHEEL MAGNETO (1) Install charge coil

5-4-15 BLOWER HOUSING AND RECOIL STARTER (1) Attach blower housing to crankcase. Tighten five flange bolts. M6 x 12 mm flange bolt : 5 pcs. Ins

(5) Install carburetor to cylinder head hooking governor rod to governor lever and throttle lever of carbu- retor. Hook rod spring over gover

(7) Adjust governor system. (a) Turn the speed control lever all the way toward the high speed position and fix it by tightening self lock

5-5 BREAK-IN OPERATION An engine that has been completely overhauled by being fitted with a new piston, rings, valves and connecting rod should

(2) At lower engine revolution, when the flywheel reached the ignition point the low speed ignition timing control circuit operates to

6-3 WIRING DIAGRAM 0 STANDARD Ignition Coil Connector Stop Switch Spark plug /// Flywheel Fig. 6-2 0 ENGINE WITH ELECTRIC STARTER Electric starter

7. AUTOMATIC DECOMPRESSION SYSTEM EH36, 41 engines are employing the automatic decompression system as a standard feature. This enables easy

EH41 I MODEL EH41 B EH41 DS EH41 D EH41 BS Air-Cooled, 4-Cycle, Single-Cylinder, Horizontal P.T.O. Shaft, OHV Gasoline Engine I Bore x Stroke 8

8. CARBURETOR 8-1 OPERATION AND CONSTRUCTION 8-1 -1 FLOAT SYSTEM The float chamber is located below the carbure- tor body and, with a float and a ne

8-1-2 PILOT SYSTEM n The pilot system feeds the fuel to the engine during idling and low-speed operation. The fuel is fed through the main jet t

8-2-2 CHOKE SYSTEM B (1) Remove the Phillips screw (6) and choke valve (7), and pull out the choke shaft (8). (2) When reassembling the choke

9. STARTING SYSTEM 9-1 RECOIL STARTER Trouble in the recoil starter rarely happens while it is in normal operation. If the starter develops

(5) Remove each part in accordance with Fig. 9-3 1. Center screw 2. Friction plate 3. Friction spring 4. Ratchet 5. Ratchet spring 6. Reel T

(4) Pass the starter rope through the starter knob and tie the rope end to make a tight overhand knot as shown in Fig. 9-6. Then put the k

9-1-3 CHECK AFTER REASSEMBLY - (1) Pull the starter knob a few times to check if : I A. The starter knob is too heavy to pull, check that eac

9-2 ELECTRIC STARTER i". I NOTE; 1 For Electric starter operation, electric wiring should be connected among electric starter, magnetic sw

9-2-2 COMPORNENT PARTS Fig. 9-11 - 55-

The following three conditions must be fulfilled for satisfactory engine start. 1. The cylinder filled with a proper fuel-air mixture. 2. G

2. PERFORMANCE 2-1 MAXIMUM OUTPUT The maximum output is the output of an engine with its throttle valve fully opened under the conditi

(4) Incorrect Valve clearance If the correct compression is not obtained even after remedying the above, disassemble the engine and check furth

10-4 ENGINE OVERHEATS (1) Crankcase oil level low. Add oil immediately. (2) Spark timing incorrect. (3) Low grade gasoline is used, or engin

11. INSTALLATION - I Engine life, ease of maintenance and inspection, frequency of checks and repairs, and operating cost all depend on t

12. SERVICE DATA 12-1 CLEARANCE DATA AND LIMITS ITEM ' Valve seat contact width Valve guide inside dia. ~ ~~ IN. EX. Unit : mm (in: EH36EH

Unit : mm (in) ~ :YLINDER Inside dia. ' Roundiness after reboring. ' Cylindricity after reboring. 'I ST0 N ' Piston size (At

Unit : mm (in) EH36EH41 ITEM STD Limit 0.15 (0.006) 0.1 5 (0.006) 0.20 (0.008) 0.05 - 0.09 (0.002 - 0.0035) 'ISTON ' Ring groove side cleara

Unit : mm (in ITEM CONNECTING ROD Big end inside dia. Clearance between big end and crankpin Small end inside dia. * Clearance between smal

EH36EH41 ITEM STD Limit CAMSHAFT Cam height (1N. and EX.) a 35.26 - 35.46 (1.3882 - 1.3961) 35.1 1 (1.3823) I * Journal outside dia. "D" t

Unit : mm (in) EH36EH41 I ITEM TAPPET Stem outside dia. VALVE SPRING FREE LENGTH VALVE SEAT ANGLE (IN. and EX.) Valve cutter angle (a) * Valve co

12-2 TORQUE SPECIFICATIONS ITEMS I Tightening torque I Cylinder head bolts I 33.3 -41.2 I 340 - 420 I 24.6 - 30.4 I Connecting rod cap bolts 22.1 -

2-4 PERFORMANCE CURVES EH36 ( ) for type B t kgf-m (5.6) 2.8 (5.4) 2.7 (5.2) 2.6 !!j (5.0) 2.5 (4.8) 2.4 (4.6) 2.3 (4.4) 2.2 HP 12 11 10 9 8 7 6 5

13. MAINTENANCE AND STORAGE w The following maintenance jobs apply when the engine is operated correctly under normal conditions. The indicated

13-4 EVERY 100-200 HRS. (MONTHLY) MAINTENANCE ,"-. MAINTENANCE ITEMS REMARKS 1) Clean fuel filter and fuel tank. 2) Inspect cooling sys

SU6ARU ~bin America, Inc. 940 Lively Blvd. l Wood Dale, IL 60191 l Phone: 630-350~8200 l Fax: 630-350-8212 e-mail: [email protected] l www.ro

EH41 kgfom (5.8) 2.9 1 w (5.6) 2.8 - (5.2) 2.6 I- HP 14 13 12 11 10 9 8 7 6 5 4 3 ( for tvpe B Nom (56) 28 (54) 27 (52) 26 kW 10.0 9.0 8.0 7.0 6.0 5.

1. The overhead valve design offers a compactness, light weight and ideal combustion characteristics resulting in more power from less