Raw Water Pumps

One of the most common items you'll replace on your boat is the water pump impeller.  Whether you are fixing a worn-out inboard engine water pump, rebuilding your stern drive or performing routine maintenance on your outboard motor, you'll likely be replacing an impeller as part of the job.

What is the Impeller, Exactly?

The impeller is a flexible rubber gear that creates the vacuum needed to pump water into your engine for cooling.  Since it is always in use when the engine is running, the impeller suffers a lot of wear and tear.  You should inspect the impeller at least once a year.  It is not uncommon for the impeller vanes to tear or break off, causing potential blockage in the cooling system and a loss of water pressure.  Additionally, impellers can swell, crack or bend, which can affect the ability of the pump to cool the engine.  Another possible defect is when the metal hub of the impeller detaches from the rubber, causing a situation where the hub is spinning but the

Our goal is to educate you about the purpose and function of many of the marine parts required to keep your boat running smoothly. Whether you're a veteran seaman or a novice, one thing you all know is that a boat comes equipped with hundreds of moving parts.

No one person can know everything there is to know about the proper functioning of every boat part. That's why we've tapped the collective wisdom of our long-time technical experts to share their knowledge and expertise.

What You Need to Know About the Indmar LTR/LT1 Bronze Raw Water Pump

This Indmar raw water pump is crankshaft driven and mounted directly to the crankshaft harmonic balancer rather than accessory mounted and pulley driven by a belt. It is a priority part made specifically for Indmar by Johnson Pump to fit specific engines which makes it's available only through Indmar. Being OEM specific means you have to go directly to an Indmar authorized reseller to obtain a replacement pump.

This raw water pump fits only the LT1

Our goal is to educate you about the purpose and function of many of the marine boat parts required to keep your boat running smoothly. Whether you're a veteran seaman or a novice, one thing you all know is that a boat comes equipped with hundreds of moving parts.

Our goal is to educate you about the purpose and function of many of the marine parts required to keep your boat running smoothly. Whether you're a veteran seaman or a novice, one thing you all know is that a boat comes equipped with hundreds of moving parts.

What You Need to Know About the Sherwood G21 Raw Water Pump

The Sherwood G21 raw water pump is unique to Pleasurecraft (PCM) engines and used specifically on the 302/351 Ford engines. They were used for decades with no design changes, so there’s a lot of service replacement for it. Like other raw water pumps, it will require maintenance and service.

The wakeboard and towboat markets are full of passionate people, so these engines get used quite a bit more than the standard

Our goal is to educate you about the purpose and function of many of the marine parts required to keep your boat running smoothly. Whether you're a veteran seaman or a novice, one thing you all know is that a boat comes equipped with hundreds of moving parts.

No one person can know everything there is to know about the proper functioning of every boat part. That's why we've tapped the collective wisdom of our long-time technical experts to share their knowledge and expertise.

What You Need to Know About the Sherwood Raw Water Pump for Crusader

The Sherwood raw water pump was used at Crusader from the 1970s through 1992 which they installed on the majority of engines they built. Thus, Sherwood produced a vast number of these pumps. It does require maintenance, service, and winterization.

The raw water pump is used to bring the lake water or ocean water or river water to the engine for cooling. It’s used whether it’s a raw-water-cooled engine or freshwater-cooled (FWC) engine/close-cooled