Subaru Robin Power Products EH12-2, EH17-2, EH25-2 manual Ft4b

Page 41

5-4-8CYLINDERHEAD

(1)Cleancarbonandgumdepositsfromthevalves,seats,portsandguides.Inspectthevalves,valve seats and valve guides.

(2)Replace valves that are badly burned,pitted or warped.

(3)Wheninstallingthevalves in thecylinderhead, oil thevalvestemsandinsertthemintothevalve guide.

Thenplacethecylinder head on aflat table, installthevalvesprings,springretainers and collet valves.

(4)Valveguidesshould be replacedwhenthevalvestemclearanceexceedsspecifications(See "SERVICE DATA").

Draw the valve guides outand press the new guidesin. Refer to"SERV1CE DATA"for clearance specifications.

After replacing the valves and guides, lap valves in place until a uniform ring shows around the face of the valve. Clean valves and wash cylinderhead thoroughly.

(5)Install cylinder head to cylinder with new head gasket.

Tighten four flange bolts evenlyin three steps by the following tightening torque: Cylinderhead M8 X 65 mmflangebolt - - 4 PCS. (EH12-2,17-2)

M10 X 75 mm flangebolt - 4 pcs. (EH25-2)

Tightening torque(EH12-2,17-2)

 

Tightening torque(EH25-2)

1st step

2nd step

final step

1st step

2nd step

final step

5 Nom

10

Nom

23-26 N m

9.8

Nom

19.6

Nom

33.3-41.2Nom

50 k g w n

100

kgcm

230-270 kgcm

100

kgecrn

200

kgcm

340-420 kg-cm

3.6 ft-lb

7.2 ft-lb

17-30 ft-lb

7.2 ft-lb

14.5

ft4b

24.6-30.4ft*lb

54 - 9 ROCKER ARMS AND PUSH RODS

(1)Insert push rods into crankcase.

Put push rod tip in the hollow of tappet top.

(2)Apply oil to the rocker arms and assemblethem to the cylinder head using pivot bolt and guide plate.

n

5-4-10VALVE CLEARANCEADJUSTMENT

(1) Positionthepistonatthetopdeadcenter of thecompressionstroke.The topdeadcentermaybe obtained by placing the key sloton the power take off shaft to :

I I

12o'clock

EH12-2B,17-2B,25-2D

I

I

10o'clock

EH12-2D,17-2D,25-2B

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Contents Page Contents Page Specifications EH17-2 EH25-2 2 5 2 6 s EH25-2D EH25-2DS 1MAXIMUMOUTPUT +3l2 Kgfam 3000 Features Crankshaft is forged carbon steel, and the crank 6CAMSHAFT 9GOVERNORSYSTEM To effectively reduce vibration Decompression System 17SECTIONAL View of Engine Rocker ARM Push ROD Disassembly and Reassembly Disassemblyprocedures Fuel tank Close fuel valve Recoil starter Housing Oil sensor Option 1pc. EH25-2 Starter 2pcs Procedures Remove starterpulley from flywheel M6 X 25mm Screw Procedures Remarks Fastening Be careful not to damage Step Remove piston rings from piston Be careful not to damage Intake valve Loosen nut and remove bolt pivot Inspect Valves 4REASSEMBLY Procedures Precautions for Reassembly Valve Recess 54-4CONNECTING ROD Tappet Andcamshaft Spacer Shims EH12-2,17-2 Ft4b Spark plug 54-16GOVERNOR System Refer to the illustrations below. SeeFig Install the muffler to the cylinder head Flange nut ... pcs Ignition System 1000 3WIRING Diagram Automatic Decompression System Carburetor 21 -@ Float System Starting System CbI Do not abruptly put off your Page IO. Troubleshooting 10-1-3IGNITIONSYSTEM 10-5ENGINE Knocks Installation Service Data STD Lmit Uni rnm STD Limit EH12-2 STDLimit EH17-2 LTEM Valve Limit 3134 EH25-2 Description Tightening Torque 12-3OIL Grade Chart Maintenance and Storage Clean fuelfilter and fuel tank Page SU6ARU

EH12-2, EH17-2, EH25-2 specifications

Subaru Robin Power Products has established a reputation for quality and reliability in the world of small engines, especially with their EH Series engines: EH12-2, EH17-2, and EH25-2. Each of these models brings unique benefits and advanced technologies, catering to various applications for both commercial and personal use.

The EH12-2 is a compact engine designed for lightweight applications. Weighing in at just 66 pounds, it is ideal for portable equipment and general-purpose applications. Its 4-stroke design allows for lower emissions and greater fuel efficiency compared to traditional 2-stroke engines. The EH12-2 features a low-profile design that enhances stability while operating. Its overhead cam design enables better performance at higher RPMs, making it ideal for tasks that require consistent power and reliability.

Moving up in size, the EH17-2 boasts a more robust configuration, making it suitable for semi-professional applications. With a displacement of 169cc, this engine provides higher torque and improved performance for heavier machinery. The EH17-2 also incorporates Subaru’s advanced air filtration technology, which extends engine life and reduces maintenance frequency. This engine is particularly suited for applications such as generators, pressure washers, and other equipment requiring sustained power output.

Finally, the EH25-2 stands as the powerhouse of the series. With a displacement of 252cc, it delivers exceptional torque and horsepower for demanding tasks. The EH25-2 employs Subaru's patented electronic ignition system, offering easy starts and consistent performance in a range of conditions. Its multi-point lubrication system ensures that all engine parts receive adequate oil, resulting in reduced wear and tear over time. Additionally, the EH25-2's rugged construction is designed to withstand vibration and strain, making it ideal for construction and heavy-duty industrial applications.

All three engines share core features such as a user-friendly design, efficient fuel consumption, and compliance with environmental regulations. The engines are also equipped with easy-access maintenance points, helping users perform necessary upkeep without hassle. Whether for a homeowner with occasional needs or a contractor relying on dependable machinery, Subaru's EH series provides powerful and efficient solutions tailored to meet varying demands. With their focus on innovation and quality, Subaru Robin Power Products continues to evolve and improve, ensuring their engines serve diverse markets effectively.
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