Yamaha Piston Ring Kit (0.50mm Oversize) – Fits Yamaha 25-30HP Outboards
Yamaha Piston Ring Kit (0.50mm Oversize) – Fits Yamaha 25-30HP Outboards is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Product Details
This is a Yamaha Piston Ring Kit (0.50mm Oversize), designed for a range of Yamaha 25-30HP 2-Stroke outboard engines manufactured between 1996 and 2010. It is compatible with models including the 25VE/VM, 25B/BMH, 30G/GE, and C-series engines, ensuring a precise fit for engine rebuilds requiring an oversize specification.
This kit serves as a direct replacement for Yamaha OEM part number 61N-11605-00-00.
- Installation is specific to compatible engine models.
- Designed for use with gasoline (petrol) fuel systems.
- This is a 0.50mm oversize piston ring set for cylinders that have been bored out.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 61N-11605-00-00 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha engines, please verify your specific model and year against the compatibility list. This kit is intended for the models listed that require a 0.50mm oversize ring set.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | 25VE/VM | 25 | 2-Stroke | 1996–2001 | 61N-11605-00-00 |
| Yamaha | 25B/BMH | 25 | 2-Stroke | 2001–2010 | 61N-11605-00-00 |
| Yamaha | 30G/GE | 30 | 2-Stroke | 1996–2000 | 61N-11605-00-00 |
| Yamaha | C30ERR (C30ELRR) | 30 | 2-Stroke | 1993 | 61N-11605-00-00 |
| Yamaha | C30(MH/ER)S | 30 | 2-Stroke | 1994 | 61N-11605-00-00 |
| Yamaha | C30ERT | 30 | 2-Stroke | 1995 | 61N-11605-00-00 |
| Yamaha | C30ERU | 30 | 2-Stroke | 1996 | 61N-11605-00-00 |
| Yamaha | C30ELRV | 30 | 2-Stroke | 1997 | 61N-11605-00-00 |
Technical Specs
- Product Type
- Piston Ring Kit (0.50mm Oversize)
- Installation
- Engine Specific
- Fuel Type
- Gasoline (Petrol)
- Dimensions
- Height: 13 mm (0.51 in), Width: 75 mm (2.95 in), Length: 75 mm (2.95 in)
- Weight
- 0.04 kg (0.09 lb)
- Other Technical Attributes
- 0.50mm oversize specification
What’s in the Box
- 1 x Piston Ring Set (0.50mm Oversize) (61N-11605-00-00)
Installation Notes
- Disconnect the battery and ensure the engine is cool before beginning work.
- Drain the engine oil and coolant.
- Carefully remove the cylinder head and any other components obstructing access to the pistons.
- Remove the old piston assemblies from the cylinders.
- Gently remove the old piston rings from the pistons using a ring expander tool.
- Thoroughly clean the piston ring grooves to remove all carbon deposits.
- Install the new piston rings onto the pistons, ensuring they are in the correct order and orientation.
- Lubricate the cylinders and new rings with fresh engine oil.
- Reinstall the piston assemblies, using a ring compressor to guide them into the cylinders.
- Reassemble the engine components in reverse order of removal, torquing all bolts to manufacturer specifications.
- Refill the engine with new oil and coolant.
- Reconnect the battery and test the engine, checking for leaks and proper operation.
Troubleshooting & FAQ
How do I know if I need 0.50mm oversize piston rings?
Oversize rings are required when a cylinder has been machined or "bored" to a larger diameter to correct for wear or damage. You should only purchase this kit if your engine's cylinders have been specifically measured and machined to require a 0.50mm oversize set.
What are the signs of failing piston rings?
Common symptoms include excessive blue or white smoke from the exhaust, high oil consumption, poor engine compression, and a noticeable loss of power. These signs indicate that combustion gases are blowing past the rings or oil is leaking into the combustion chamber.
Will this kit work for a standard, non-bored cylinder?
No. This kit is specifically for cylinders that have been bored 0.50mm over the standard size. Using these rings in a standard cylinder will cause engine damage. You must use standard-size rings for a non-machined cylinder.
Is this a complete set for one piston?
Yes, this kit contains all the necessary rings for a single piston assembly as specified. If you are rebuilding multiple cylinders, you will need to purchase one kit per piston.
How often should piston rings be replaced?
Piston rings do not have a fixed replacement interval. They are typically replaced during an engine rebuild, which is performed only when there are clear signs of wear, such as low compression or high oil consumption.
Do I need special tools for installation?
Yes, professional installation is highly recommended. Specialized tools such as a piston ring expander, a piston ring compressor, and a torque wrench are essential for proper and safe installation.
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.
Payment & Security
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