Robin America EH25-2 Specifications

0 EHf7D, B n ( ) for B type .. " REVOLUTION "-+ r.p.m. kg-m 1 .I 0 ,(2.2) t I 1-00 (2.0) I W Y 0.9 (1.8) 6 CT 0 I- CoNTiNuous RETE0 HP 1 RE

0 EH25D, 6 -7-

3. FEATURES 1. The overhead valve design offers a compactness, light weight and ideal combustion characteristics 2. An optimum lubrication

4-3 CRANKSHAFT The crankshaft is forged carbon steel, and the crank pin is induction-hardened. 0 The output end of the shaft has a crankshaf

4-6 CAMSHAFT ‘I’he camshaft for the D-type engine is made of special cast iron and camshaft gears are casted togcther in one piece. Both s

4-9 GOVERNOR SYSTEM The governor is a centrifugal flyweight type which ensures constant operation at the selected speed against load variations

4-12 IGNITION SYSTEM The ignition system is a transistor controlled magneto ignition system which cosists of a fly- wheel and an ignition coil

4-15 SECTIONAL VIEW OF ENGINE / FLYWHEEL FUEL TANK / I II + . PISTON I MAIN BEARING COVER - 13 -

ROCKER ARM I L - 14 -

5. 5-1 CAUTIONS 1) Because some mating parts with wear surfaces were machined together when the engine was manifactured, or have establi

ROBIN AMERICA, INC. ROBIN TO WISCONSIN ROBIN ENGINE MODEL CROSS REFERENCE LIST ROBIN EY08 EY15 EY 15V EY20 EY2OV EY23 EY28 EY3 5 EY40 - EY45V EY2 1

5-3 DISASSEMBLY PROCEDURES Step Tool Remarks Procedures Part to remove I 14mm box wrench Be careful not to lose the (I) Remove oil drain plug and drai

step 2 Part to remove Fuel tank Procedures (1) Close fuel valve. (2) Disconnect fuel hose between fuel strainer and carburetor. (3) Remove fue

I Step I Part to remove 1 Procedures I Remarks ~~ 3 (I) Remove recoil from blower housing. Recoil starter M6 X8mm flange bolt -.a- 4pcs. 4 M6X I2mm fl

Step 6 - 7 'art to removc Muffler cover Muffler and Muffler bracket Exhaust manifold and Manifold cover Procedures (1) Remove muffler cover. M

Step a Part to remove Control box and Electric starter (Option) Procedures (I ) Disconnect wires. blue 1 (diode rectifier ) light blue I (diode re

Step I Part to remove I Procedures ~~~~ 9 (1) Remove head cover from crankcase. Head cover M6x 12mrn flange bolt -.-- Ipc. 10 (1) Remove cleaner

Step 11 - 12 13 14 - I Part to remove Governor lever, Governor rod and Governor spring Procedures (1) Unhook governor spring from speed control lev

15 Starter pulley 16 Flywheel I 17 1 Charge coil (Option) Procedures (1) Remove starter pulley from flywheel. Place socket wrench on flywheel f

Step 18 19 20 - Part to remove 1 Procedures I Remarks ~~ ~ ~~ Ignition coil (I) Disconnect ignition plug cap and remove ignition coil from crank

Step 21 - - 22 - Part to remove Rocker Cylinder head Procedures I Remarks (1) Remove cylinder head from crankcase. M8X65mm flange bolt .+.. 4pcs. (

NTEN'TS Section Title Page 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . SPEClFlCATlONS ...

Step 23 Part to remove 1 Main bearing cover Procedures (I) Remove main bearing cover fastening bolts. M6X30mm bolt and washer 8pcs. (EHI2,17) M

Step 24 25 - Part to remove I Procedures Cam shaft add (I) Remove cam shaft from crankshaft. Balancer shaft (2) Remove balancer shaft. (EH25 onl

Step 26 27 Part to remove Connecting rod and Piston Procedures ... . . . . .. . ." . . . . . . . (1) Remove connecting rod bolt after scra

Step Tool Remarks Procedures Part to remove 28 Be careful not to damage (I) Remove crankshaft tapping at the Crankshaft flywheel end. oil seal. Fig.

Procedures ~~~~ (1) Loosen adjusting screw on rocker arms. (2) Pull out rocker arm shaft from the intake side of the cylinder head. (See Fig.

5-4 REASSEMBLY PROCEDURES 0 PRECAUTIONS FOR REASSEMBLY 1) Clean parts throughly before reassembly. 2)Scrape off all carbon deposits from cyli

TOP RING SECOND RlNC OIL RING I Fig. 5-28 5-4-3 PISTON AND CONNECTING ROD (1) When installing the piston on the connecting rod, place ‘‘4 ” mar

(2) Install the piston and connecting rod assembly into the cylinder. Use a piston ring compressor to hold the piston rings. Place ‘‘4 ” mark of t

54-5 BALANCER SHAFT (EH25 type only) Install balancer shaft aligning the timing mark on the balancer shaft gear and the balancer gear

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

13-1 13-2 13-3 13-4 13-5 13-6 13-7 .. "

Fig. 5-36 (2) Lubricate the oil seal and bearing surfaces. Add a light film of oil on the main bearing cover face to hold the gasket in place. Pla

5-4-8 BREATHER VALVE Attach breather plate (breather valve) and breather cover to crankcase using proper gaskets. Replace gaskets with n

(2) Loosen the lock nut on the rocker arm and turn the adjusting screw to adjust the clearance between the rocker arm and the valve

5-4-14 FLYWHEEL MAGNETO (1) Install the charge coil to the crankcase. (Option) - [NOTE) B Be careful not to pinch coil wire between charge coi

(3) Connect the speed control lever and the governor lever with the governor spring. The governor spring should be hooked to the number 2

5-4-19 AIR CLEANER Install the air cleaner gasket and the cleaner case and tighten them with 2-M6 flange nuts. rn Then install the eleme

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

2) At the higher engine speed Rotation of the flywheel generates the current I, as this current flows through the base terminal of the powe

6-3 WIRING DIAGRAM STANDARD Ignition Coil - r=+ Spark Plug TfT Flywheel Stop Button Connector w 3 _1 m ElNGlNE WITH ELECTRIC STARTER I MAGNETIC SW

7. AUTOMATIC DECOMPRESSION SYSTEM EH12, 17, 25 engines are employing the automatic decompression system as a standard feature. The automatic

1. SPECIFICATIONS ~~ ~~ ~ EH12 EH12B EH12DS EH12D EH12BS Model TY Pe Air-Cooled, 4-Cycle, Single-Cylinder. Horizontal P.T.O. Shaft, Gasoline Eng

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

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

8-2-4 MAIN SYSTEM (1) Remove the bolt(l2)and take out float chamber body(l3). (2) From the body (14) remove the main nozzle (15), and then rem

9. STARTING SYSTEM 9-1 RECOIL STARTER When repairing recoil starter, disassemble and reassemble in the following procedures. Tools : Socket wr

(4) Remove the reel from the starter case as shown in Fig. 9-3. Take out the reel slowly turning it lightly towards the left and right to

(3) Prior to installing the reel in the starter case, wind the starter rope in the reel for 2.5 turns in the arrowhead direction as shown in F

(6) Test the operation of the recoil starter to see if the rope recoils satisfactorily and the ratchets project and retract properly. M

IO. TROUBLESHOOTING The following three condit.ionts must be fulflled for satisfactory engine start. 1. The cylinder filled with a proper

10-1-3 IGNlTfON SYSTEM Check the followings for lack of sparks. (1) Wires of the ignition coil, spark plug or contact breaker disconnected. (2)

10-5 ENGINE KNOCKS (1) Poor quality gasoline. (2) Engine operating under heavy load at low speed. (4) Spark timing incorrect. (5) Loose connec

Model TY Pe Bore X Stroke Piston Displacement Compression Ratio Continuous output Max. Torque Direction of Rotation Cooling system Valve Arrange

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

12. SERVICE DATA “STD” in the following table is the parts dimension from the brand new engine or the spare parts. Whereas, “Limit” shows

Unit: mrn (in) T T EH12 EH17 ITEM STD Lmit STD Lmit CYLINDER Inside dia. To be rebored when the difference Detween max. and min. of diameter reached

Unit : mm (in) 1 I ITEM EH25 t STD Lmit CYLINDER 0 Inside dia. To be rebored when the difference between max. and min. of diameter reached to 0.1 (0.0

T EH12 7 Ek ITEM Ring groove side clearance STD Limit STD Limit 0.030 - 0.075 :0.0012 - 0.0030 0.1 5 (0.006) 0.035 - 0.080 (0.001 4 - 0.0031 0.1 5

Unit: mm (in) T EH25 ITEM Ring groove side clearance STD Limit 0.050 - 0.090 (0.0020 - 0.0035) 0.1 5 (0.006) 0.030 - 0.070 (0.001 2 - 0.0028) 0.1 5

Unit: mrn (in) ITEM 0 Clearance between big end and crankpin Small end inside dia. I Clearance between small end I Big end side clearance I CRANKSHAF

Unit: mm (in) 0 Clearance between small end and piston pin 0 Big end side clearance " CRANKSHAFT 0 Journal dia. ~~~ EH17 STD Limit 30.000 - 30.01

Unit: mm (in) ITEM CONNECTING ROD Big end inside dia. 0 Clearance between big end and crankpin Small end inside dia. 0 Clearance between small end and

Unit: mrn (in) CAMSHAFT Cam height 0 Journal outside dia. "D" type ITEM IN.EX. CAMS VALVE Valve stem outside dia. Clearance between

I Et125 Model EH25B EH25BS EH25D EH25DS TY Pe 1 Air-Cooled, 4-Cycle, Single-Cylinder, Horizontal P.T.O. Shaft, Gasoline Engine Bore X Stroke 75 X

Unit : mm (in) ITEM CAMSHAFT Cam height 0 Journal outside dia. "D" type Y VALVE Valve stem outside dia. Clearance between valve stem

Unit : mm (in) ITEM TAPPET 0 Stem outside dia. 0 Guide inside dia. 0 Tappet guide clearance ROCKER ARM 0 Rocker arm hole dia. Rocker arm shaft clearan

Unit: mm (in) ITEM T TAPPET Stem outside dia. 0 Guide inside dia. 0 Tappet guide clearance ROCKER ARM Rocker shaft outside dia. 0 Rocker arm hole dia

Unit: rnrn (in) T EH12/17/25 ITEM VALVE SEAT ANGLE(IN. EX.) 0 Valve cutter angle(a) 0 Valve contact width(b) 12-2 TORQUE SPECIFICATIONS EH12/17type

12-3 OIL GRADE CHART Specificd Ihricant Cluality Single grade Multi- grade I Comparison between oil viscosity and temparature I 5w 10 w 1 20 w # 20

13. MAINTENANCE AND STORAGE 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 REMARKS I) Clean fuel filter and fuel tank. 2) Inspect cooling system and remove dirt a

.

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

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Industrial Engines

2-4 PERFORMANCE CURVES 0 EH12D, B 4.0 (2.98 KW) 3.5 (2.61 KW) 3.0 (2.24 KW) 2.5 (1.87 KW) 2.0 (1.49 KW) 1.5 (1.21 KW) 1 .o (0.75 KW) 0.5 (0.37 KW