1. Technical Specifications

2. Key Features

• Heavy-Duty Forged Alloy Steel: Precision drop-forged from premium alloy steel with optimized grain flow, delivering exceptional tensile, yield, and fatigue strength under continuous high-RPM loads.

• Precision CNC Bores & Honing: Big-end and small-end pin bores are CNC precision bored and honed to micron-level roundness, maintaining a stable hydrodynamic oil film and preventing bearing spun.

• Strict Weight-Matching Balance: Each rod is balanced within narrow gram tolerances across both small and big ends to eliminate secondary engine harmonics and minimize vibration.

• Direct OEM Fitment: Center-to-center length, big-end journal width, and wrist pin bore diameters conform strictly to factory engineering drawings for exact drop-in fitment.

3. Compatible Models

Primarily compatible with Yamaha 2-cylinder 4-stroke 362cc outboard platforms:

• Yamaha 4-Stroke F15 Series: F15C, F15CES, F15CML, F15CMS, F15CPL (2006 and newer 6AH platform)

• Yamaha 4-Stroke F20 Series: F20B, F20BMH, F20BES, F20BML, F20BPS (2006 and newer 6AH platform)

• Outboard Clones: Compatible with Parsun (F15A / F20A), Hidea (HDF15 / HDF20), and other outboards based on the Yamaha 6AH architecture

4. Aftermarket & Brand Compatibility

• OEM Brand Fitment:

• Yamaha Marine: Designed for genuine Yamaha F15C and F20B 4-stroke powerhead reciprocating assemblies.

• PREMARINE Brand Aftermarket Replacement:

• PREMARINE Quality Standard: PREMARINE specializes in high-reliability marine engine internals, connecting rods, and powerhead rebuild components. This connecting rod assembly is manufactured with closed-die forgings and precision CNC machining lines.

• Direct OEM-Level Performance: Center distance tolerances, bolt clamping yield strength, and dynamic balancing meet or exceed OEM specifications, serving as the premier cost-effective choice for major engine overhauls.

5. Common Symptoms & Troubleshooting

• Deep Metallic Knocking Sound from Crankcase (Rod Bearing Knock):

• Cause: Low oil pressure, emulsified engine oil, or heavy thermal loading causing excessive rod bearing journal clearance.

• Troubleshooting: Measure rod bearing oil clearance with Plastigage; if clearance exceeds service limits or the big-end bore is out-of-round, replace the connecting rod and bearing inserts.

• Engine Seized / Starter Unable to Crank (Spun Bearing):

• Cause: Lubrication starvation causing the bearing shells to friction-weld to the crankshaft journal and rod cap.

• Troubleshooting: Dismantle crankcase and inspect for heat discoloration (blueing); heat-damaged rods must be replaced immediately.

• Low Cylinder Compression / Piston Not Reaching TDC (Bent Rod):

• Cause: Hydro-locking caused by water ingestion into the combustion chamber (liquid cannot compress).

• Troubleshooting: Check connecting rod straightness and bend alignment during rebuilds; replace any rod exhibiting plastic deformation.

OEM Part Numbers

Compatible OEM references include:

6AH-11650-00

6AH-11650-00-00

Compatible Engine Models

This Connecting Rod Assembly is primarily designed for:

4-Stroke 15/20HP

If you are unsure about compatibility, please provide your engine model number or identification plate for verification before ordering.

Applications

This Connecting Rod Assembly is commonly used for:

Outboard engine repair

Engine rebuilding projects

Marine maintenance workshops

Boat fleet maintenance

Commercial fishing vessels

Recreational boats

Marine spare parts distribution