Impeller for Yamaha/Mariner 40–70 HP (2 & 4-Stroke) – OEM Quality Reliability

This versatile impeller covers the cooling needs of many Yamaha/Mariner engines from 40 HP to 70 HP – including both two-stroke and four-stroke models. It delivers OEM-level quality since it is manufactured to the same dimensions and from materials comparable to the original. If you want trouble-free engine cooling and aim to avoid costly overheating repairs, this impeller is the right choice for your routine maintenance.

• Compatibility: The impeller is compatible with the following groups of engines:
  • Yamaha 2-Stroke: 40, 50, 55, 60, 70 HP models (approximately late 1970s through early 2000s). This includes popular series like the Yamaha 40V/50H (twin cylinder), 60F/70B (triple cylinder), etc., where the original impeller carries part #6H3-44352-00 or the updated #69-44352-00.
  • Yamaha 4-Stroke: First-generation Yamaha 40HP, 50HP, and 60HP 4-stroke engines (e.g., F40A/F50A/F60A from the late 1990s and early 2000s) which share water pump impeller compatibility with their 2-stroke predecessors.
  • Mariner/Mercury Equivalents: Some Mercury/Mariner 40–60 HP 4-stroke engines (especially those co-developed with Yamaha in the late ’90s) and Mariner 2-stroke models 40–60 HP also use this impeller size. For example, the Mercury 40/50/60 EFI 4-strokes (circa 2001–2005) that were Yamaha-based, or Mariner 60HP 2-strokes (1990s). To be sure, check if your old impeller corresponds to the OEM numbers mentioned.
• Use Cases: Engines of 40–70 HP are favored for small to mid-sized vessels – from 4-meter fishing skiffs and utility boats up to ~5-meter family runabouts. They often operate under varied conditions: slow trolling, frequent start-stops, as well as full-throttle runs when getting on plane or cruising. This impeller provides reliable cooling in all these scenarios, keeping the engine’s operating temperature steady.
• Performance: With a new 6-blade impeller, your water pump will regain its full capacity. The inner diameter (~18.0 mm) and outer diameter (~51.8 mm) are precisely to spec, meaning a correct fit onto the drive sleeve and within the pump housing. This translates to optimal water pressure and flow. As a result, the engine won’t overheat even when you push it hard – for instance, going against a strong current or carrying a fully-loaded boat with crew and gear. You can maintain confidence in your engine’s cooling whether you’re idling in no-wake zones or running wide-open across the lake.
• Quality: CEF manufactures this impeller using top-grade elastomer materials that resist aging, temperature fluctuations, and the effects of saltwater. In practice, you get the same quality as the original impeller that came with your motor from the factory. The blades are flexible yet tough – they won’t crack or distort easily, which ensures a long service life. By installing this part, you’re effectively restoring your engine’s cooling system to factory performance.
• Recommendations: To keep your engine running reliably, replace the impeller regularly. A good rule of thumb: inspect it annually and replace it every 1–2 years depending on usage. If you notice a weaker tell-tale (indicator) water stream or higher running temperatures, plan to replace it as soon as possible. Also, if you operate your boat in silty or sandy waters, consider more frequent changes, as abrasive particles can wear the impeller faster. By keeping the cooling system in top shape, you protect your Yamaha/Mariner engine from overheating and ensure worry-free outings on the water.