Impeller Compatible with Yamaha 9.9/15HP/15D Outboard Engines – 40x13x22mm

Description

Keep your Yamaha outboard cooling system working properly with this compatible water pump impeller, designed to suit Yamaha 9.9HP, 15HP, and 15D outboard engines where the correct size and style is required. The impeller is the heart of the outboard’s water pump, drawing water through the intake and circulating it through the engine to prevent overheating. Over time, impellers naturally wear, harden, crack, or lose flexibility, especially in saltwater use, after long storage periods, or if the engine has ever run with reduced water supply. Replacing the impeller as part of routine servicing is one of the most important maintenance tasks you can perform to protect the engine and ensure reliable cooling performance. With a listed size of 40 x 13 x 22mm, this impeller is intended to match the required fit for the specified Yamaha applications, helping restore strong water flow and stable engine temperature. It is a practical replacement choice for preventative maintenance and dependable performance on every trip.

Interchangeable with Sierra 18-3074

Correct size for listed Yamaha applications (40 x 13 x 22mm): This impeller is specified at 40 x 13 x 22mm, helping ensure the correct fit inside the water pump housing for Yamaha 9.9HP, 15HP, and 15D engines where this size is required. Correct sizing is essential for proper sealing, efficient pumping, and reliable water circulation. A properly fitted impeller helps maintain consistent water flow and supports stable cooling performance across idle, cruising, and higher RPM use.

Essential cooling system component for safe engine operation: The impeller is responsible for pulling water into the cooling system and circulating it through the engine to control temperature. If the impeller is worn or damaged, water flow can drop significantly, increasing the risk of overheating and engine damage. Replacing the impeller helps restore proper circulation and reduces the chance of temperature-related issues, especially when operating under load, in warm water, or during longer runs.

Helps restore strong water flow and stable temperature: A fresh impeller improves pumping efficiency and helps ensure water is delivered consistently through the cooling passages. This supports stable engine temperature, smoother running, and reduced stress on the powerhead. Weak water flow can cause poor cooling performance and may lead to warning alarms or shutdowns on some engines. Replacing the impeller helps avoid these problems and improves confidence that the engine is being cooled correctly during use.

Ideal for routine servicing and preventative maintenance: Impellers are wear items and should be inspected and replaced regularly based on operating hours, storage conditions, and water type. Boats that are used in saltwater, shallow water, or sandy environments may require more frequent servicing. Installing a new impeller as part of scheduled maintenance is a cost-effective way to prevent unexpected cooling failure and helps protect the engine from avoidable overheating damage.

Supports reliable performance after storage or seasonal downtime: Outboards that sit unused for extended periods can experience impeller blades taking a set or becoming less flexible, reducing pumping performance when the engine is restarted. Replacing the impeller before the season begins helps ensure reliable cooling from the first start. This is particularly important for engines that have been stored dry, have not been run regularly, or have been used in harsh conditions where impeller wear can accelerate.

Interchangeable with Sierra 18-3074 for cross-reference: This impeller is listed as interchangeable with Sierra 18-3074, providing a useful reference point when comparing compatible parts. Cross-referencing helps confirm you are selecting the correct impeller style for your water pump setup. While cross-references are helpful, correct fitment should always be confirmed using your engine model details and the product dimensions, ensuring the impeller matches your specific Yamaha application.

Practical replacement for dependable boating and engine protection: A properly functioning impeller is one of the most important safeguards against overheating, making it a critical service part for both everyday boating and longer trips. Replacing the impeller helps maintain consistent cooling, supports long-term engine health, and reduces the likelihood of breakdowns caused by cooling system failure. It is a simple but essential maintenance upgrade that helps keep your Yamaha outboard reliable, efficient, and ready for the water.

Replacing your Yamaha outboard impeller is a smart and necessary step in protecting your engine and ensuring reliable cooling performance. Because the impeller works continuously whenever the engine is running, it naturally wears over time and should be replaced as part of routine maintenance. A fresh impeller helps restore strong water flow, maintain stable operating temperature, and reduce the risk of overheating under load or during extended use. It is also especially important after seasonal storage, where impeller blades may harden or lose flexibility. With the listed dimensions of 40 x 13 x 22mm and compatibility for Yamaha 9.9/15HP/15D applications, this impeller offers a practical solution for servicing your water pump and keeping your engine running safely. Regular cooling system maintenance supports better reliability, improved performance, and greater peace of mind every time you head out on the water.

Please refer to the image to ensure suitability.