Yamaha Piston Kit (0.25mm Oversize) – Fits Yamaha 60HP Outboards (Replaces 6K5-11635-03K)
Yamaha Piston Kit (0.25mm Oversize) – Fits Yamaha 60HP Outboards (Replaces 6K5-11635-03K) is backordered and will ship as soon as it is back in stock.
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Yamaha Piston Kit (0.25mm Oversize) – Fits Yamaha 60HP Outboards (Replaces 6K5-11635-03K) is backordered and will ship as soon as it is back in stock.
Product Details
This Yamaha Piston Kit (0.25mm Oversize) is designed for a range of Yamaha 60HP, 2-Stroke outboard engines manufactured from 1997–2013, including E60H, E60M, and related series. It serves as a high-quality replacement for worn or damaged internal engine components, machined specifically for a 0.25mm overbore.
This kit is a direct replacement for Yamaha part numbers 6K5-11635-03 and 6K5-11635-03K, and interchanges with Asaki part 6K5-11635-03.
- Engineered for internal engine installation.
- Constructed from durable, high-grade aluminum alloy.
- Includes a complete set of piston, pin, rings, and clips for a full replacement.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6K5-11635-03K |
| Yamaha | 6K5-11635-03 |
| Asaki | 6K5-11635-03 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This piston kit is specifically designed for a range of Yamaha 60HP 2-stroke outboard engines produced between 1997 and 2013.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | E60HE | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60HM | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60H | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60MHZ | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60MLHA | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60ELHB | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60HMHD | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60MLHV | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60MLHW | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60MLHX | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
| Yamaha | E60MLHU | 60 | 2-Stroke | 1997–2013 | 6K5-11635-03K |
Technical Specs
- Product Type
- Piston Kit (0.25mm Oversize)
- Installation
- Engine internal component
- Fuel Type
- Gasoline
- Housing Material
- Aluminum alloy
- Housing Color
- Silver/metallic
- Dimensions
- 7.5 cm × 7.8 cm × 8.0 cm
- Weight
- 0.42 kg (0.93 lbs)
- Other Technical Attributes
- 0.25mm oversize piston
What’s in the Box
- 1 x Piston (6K5-11635-03K)
- 1 x Piston Pin
- 2 x Clips
- 2 x Piston Rings
Installation Notes
- Disconnect the battery and all fuel lines to ensure safety.
- Following the manufacturer's service manual, disassemble the engine block to access the cylinders.
- Carefully remove the old piston, pin, and rings. Inspect the cylinder for any scoring or damage.
- Thoroughly clean the cylinder walls and connecting rod.
- Properly lubricate the new piston, rings, and pin with 2-stroke engine oil before assembly.
- Install the new piston assembly, checking that piston rings are correctly seated and oriented.
- Reassemble the engine, ensuring all bolts are torqued to the manufacturer’s specifications.
- Professional installation by a qualified marine mechanic is strongly recommended for this component.
Troubleshooting & FAQ
How do I know if I need an oversize piston?
An oversize piston is necessary when the engine cylinder has been bored or honed beyond its standard diameter due to wear, scoring, or damage. This 0.25mm oversize kit is specifically for cylinders that have been machined to match this new dimension. Always measure your cylinder bore before ordering.
What are common signs of a failing piston?
Symptoms of a worn or failing piston include a noticeable loss of engine power, poor compression, increased blueish smoke from the exhaust (indicating oil burn), and a persistent knocking or rattling sound from the engine, especially under load.
Do I need to replace anything else with the piston?
Yes. This kit includes the piston, piston pin, rings, and clips. These components are designed to wear together and should always be replaced as a complete set to ensure a proper fit, seal, and long-term engine reliability.
Is this kit for 2-stroke or 4-stroke engines?
This piston kit is exclusively for the 2-stroke Yamaha 60HP models listed in the compatibility chart. It is not suitable for 4-stroke engines, as their design and lubrication requirements are different.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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