Water Pumps & Accessories - Multi-Stage Water Pumps

2 Stage Conversion for factory Gen 5 & 6 Sea Pumps
Your Price:
$959.99

2 Stage Sea Pump for HP525, 600SCI, and 700SCI Mercury Racing Applications

625-4176

2 Stage sea pump for HP525 ,600SCI, and 700SCI Mercury Racing applications

One of many of Hardin Marines latest cooling innovations in a new two stage sea pump for the popular Mercury Racing HP525, 600SCI, 662SCI, and 700SCI engines. Engine builders have been pleading for a solution to the lack of water that the factory sea pump delivers and Hardin Marine rose to the occasion with the development of this product. Finally an answer to failed headers from water starvation and detonating engines from under supplied intercoolers.

This pump is designed to retrofit to all Mercury Generation 5/6 engines equipped with a sea pump mounted fuel pump. This pump accepts the OEM factory mechanical fuel pumps that are integrated components in the OEM fuel system and provide additional priming support to the factory EFI system. On the supercharged engines this unit is perfect to solve the cooling system short comings of the factory single stage sea water pump system that splits the single water supply to feed the factory intercooler.

Note: Pulley is not included


Replacement Mercury Sea Pump for Mercury 1075
Your Price:
$1,249.99

Replacement Mercury Sea Pump for Mercury 1075

625-4140

Replacement Mercury Sea Pump for Mercury 1075 SCi

Built to the highest standards in order to ensure maximum performance this pump is designed to last a lifetime. This pump replaces Design I and II model pumps for Mercury 1075 SCi. Will replace OEM #'s 840048A05 and 841359A01. Pulley is Not Included. Will not replace Design III model pumps. The 3 stage inlet has a stainless down turn inlet.


Replacement Mercury Sea Pump for Mercury 1075 - Gen 1
Your Price:
$1,425.99

Replacement Mercury Sea Pump for Mercury 1075 - Gen 1

625-4141

Replacement Mercury Sea Pump for Mercury 1075 SCi - Gen 1

Built to the highest standards in order to ensure maximum performance this pump is designed to last a lifetime. This pump replaces Design I and II model pumps for Mercury 1075 SCi Gen 1. Will replace OEM #'s 840048A05 and 841359A01. Pulley is Not Included. Will not replace Design III model pumps. The 3 stage inlet has an aluminum inlet with spacer.


1 Stage Aluminum  Sea Pump
Your Price:
$599.99

1 Stage Aluminum Sea Pump

625-4900

1 Stage Aluminum Sea Pump

  • 1” NPT inlet and outlet
  • Pump churns out up to 20% more water than a stock factory pump.

The Extreme single stage pump is the perfect choice for a stock or slightly modified engine. It is designed with large 1” NPT inlet and outlet flanges that deliver the flow of water more efficiently than a stock single impeller OEM pump. By allowing direct inlet water flow these pumps churn out up to 20% more water than a stock factory pump. These pumps are fully rebuildable and will be the last pump you ever buy!

Available in: Aluminum for fresh water use or Stainless Steel for use in salt water with 1” NPT inlet/outlet and optional 1-1/4” custom billet hose barbs.


1 Stage Aluminum  Sea Pump with 1 Groove Pulley & Single 1” NPT  Inlet/Outlet
Your Price:
$659.99

1 Stage Aluminum Sea Pump with 1 Groove Pulley & Single 1" NPT Inlet/Outlet

625-4901

1 Stage Aluminum Sea Pump with 1 Groove Pulley & Single 1" NPT Inlet/Outlet

  • 1” NPT inlet and outlet
  • Pump churns out up to 20% more water than a stock factory pump.

The Extreme single stage pump is the perfect choice for a stock or slightly modified engine. It is designed with large 1” NPT inlet and outlet flanges that deliver the flow of water more efficiently than a stock single impeller OEM pump. By allowing direct inlet water flow these pumps churn out up to 20% more water than a stock factory pump. These pumps are fully rebuildable and will be the last pump you ever buy!

Available in: Aluminum for fresh water use or Stainless Steel for use in salt water with 1” NPT inlet/outlet and optional 1-1/4” custom billet hose barbs.


1 Stage Aluminum  Sea Pump with 2 Groove Pulley & Single 1” NPT  Inlet/Outlet
Your Price:
$732.99

1 Stage Aluminum Sea Pump with 2 Groove Pulley & Single 1" NPT Inlet/Outlet

625-4902

1 Stage Aluminum Sea Pump with 2 Groove Pulley & Single 1” NPT Inlet/Outlet

  • 1” NPT inlet and outlet
  • Pump churns out up to 20% more water than a stock factory pump.

The Extreme single stage pump is the perfect choice for a stock or slightly modified engine. It is designed with large 1” NPT inlet and outlet flanges that deliver the flow of water more efficiently than a stock single impeller OEM pump. By allowing direct inlet water flow these pumps churn out up to 20% more water than a stock factory pump. These pumps are fully rebuildable and will be the last pump you ever buy!

Available in: Aluminum for fresh water use or Stainless Steel for use in salt water with 1” NPT inlet/outlet and optional 1-1/4” custom billet hose barbs.


1 Stage Stainless Steel Sea Pump
Your Price:
$599.99

1 Stage Stainless Steel Sea Pump

625-4910

1 Stage Stainless Steel Sea Pump

  • 1” NPT inlet and outlet
  • Pump churns out up to 20% more water than a stock factory pump.

The Extreme single stage pump is the perfect choice for a stock or slightly modified engine. It is designed with large 1” NPT inlet and outlet flanges that deliver the flow of water more efficiently than a stock single impeller OEM pump. By allowing direct inlet water flow these pumps churn out up to 20% more water than a stock factory pump. These pumps are fully rebuildable and will be the last pump you ever buy!

Available in: Aluminum for fresh water use or Stainless Steel for use in salt water with 1” NPT inlet/outlet and optional 1-1/4” custom billet hose barbs.


1 Stage Stainless Steel Sea Pump with 1 Groove Pulley & Single 1” NPT Inlet/Outlet
Your Price:
$649.99

1 Stage Stainless Steel Sea Pump with 1 Groove Pulley & Single 1" NPT Inlet/Outlet

625-4911

1 Stage Stainless Steel Sea Pump with 1 Groove Pulley & Single 1” NPT Inlet/Outlet

  • 1” NPT inlet and outlet
  • Pump churns out up to 20% more water than a stock factory pump.

The Extreme single stage pump is the perfect choice for a stock or slightly modified engine. It is designed with large 1” NPT inlet and outlet flanges that deliver the flow of water more efficiently than a stock single impeller OEM pump. By allowing direct inlet water flow these pumps churn out up to 20% more water than a stock factory pump. These pumps are fully rebuildable and will be the last pump you ever buy!

Available in: Aluminum for fresh water use or Stainless Steel for use in salt water with 1” NPT inlet/outlet and optional 1-1/4” custom billet hose barbs.


1 Stage Stainless Steel Sea Pump with 2 Groove Pulley & Single 1” NPT Inlet/Outlet
Your Price:
$704.99

1 Stage Stainless Steel Sea Pump with 2 Groove Pulley & Single 1" NPT Inlet/Outlet

625-4912

1 Stage Stainless Steel Sea Pump with 2 Groove Pulley & Single 1” NPT Inlet/Outlet

  • 1” NPT inlet and outlet
  • Pump churns out up to 20% more water than a stock factory pump.

The Extreme single stage pump is the perfect choice for a stock or slightly modified engine. It is designed with large 1” NPT inlet and outlet flanges that deliver the flow of water more efficiently than a stock single impeller OEM pump. By allowing direct inlet water flow these pumps churn out up to 20% more water than a stock factory pump. These pumps are fully rebuildable and will be the last pump you ever buy!

Available in: Aluminum for fresh water use or Stainless Steel for use in salt water with 1” NPT inlet/outlet and optional 1-1/4” custom billet hose barbs.


2 Stage Aluminum  Sea Pump
Your Price:
$789.99

2 Stage Aluminum Sea Pump

625-4920

2 Stage Aluminum Sea Pump with 1 Groove Pulley, 1-1/4” NPT Center Inlet/Outlet

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components.

Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil cooler is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Aluminum  Sea Pump with 1 Groove Pulley, 1-1/4” NPT Center Inlet & Dual 1” NPT Outlets
Your Price:
$899.99

2 Stage Aluminum Sea Pump with 1 Groove Pulley, 1-1/4" NPT Center Inlet & Dual 1" NPT Outlets

625-4922

2 Stage Aluminum Sea Pump with 1 Groove Pulley, 1-1/4” NPT Center Inlet & Dual 1” NPT Outlets

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Aluminum  Sea Pump with 2 Groove Pulley, 1-1/4” NPT Center Inlet & Dual 1” NPT Outlets
Your Price:
$1,050.99

2 Stage Aluminum Sea Pump with 2 Groove Pulley, 1-1/4" NPT Center Inlet & Dual 1" NPT Outlets

625-4932

2 Stage Aluminum Sea Pump with 2 Groove Pulley, 1-1/4” NPT Center Inlet & Dual 1” NPT Outlets

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Aluminum  Sea Pump wit h1 Groove Pulley, 1-1/4” NPT Center Inlet/Outlet
Your Price:
$995.99

2 Stage Aluminum Sea Pump with 1 Groove Pulley, 1-1/4" NPT Center Inlet/Outlet

625-4921

2 Stage Aluminum Sea Pump wit h1 Groove Pulley, 1-1/4” NPT Center Inlet/Outlet

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Aluminum  Sea Pump with 2 Groove Pulley, 1-1/4” NPT Center Inlet/Outlet
Your Price:
$1,125.99

2 Stage Aluminum Sea Pump with 2 Groove Pulley, 1-1/4" NPT Center Inlet/Outlet

625-4931

2 Stage Aluminum Sea Pump with 2 Groove Pulley, 1-1/4” NPT Center Inlet/Outlet

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Stainless Steel Sea Pump
Your Price:
$789.99

2 Stage Stainless Steel Sea Pump

625-4940

2 Stage Stainless Steel Sea Pump

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Stainless Steel Sea Pump with 1 Groove Pulley, 1-1/4” NPT Center Inlet & Dual 1” NPT Outlets
Your Price:
$899.99

2 Stage Stainless Steel Sea Pump with 1 Groove Pulley, 1-1/4" NPT Center Inlet & Dual 1" NPT Outlets

625-4942

2 Stage Stainless Steel Sea Pump with 1 Groove Pulley, 1-1/4” NPT Center Inlet & Dual 1” NPT Outlets

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Stainless Steel Sea Pump with 1 Groove Pulley, 1-1/4” NPT Center Inlet/Outlet
Your Price:
$951.99

2 Stage Stainless Steel Sea Pump with 1 Groove Pulley, 1-1/4" NPT Center Inlet/Outlet

625-4941

2 Stage Stainless Steel Sea Pump with 1 Groove Pulley, 1-1/4” NPT Center Inlet/Outlet

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Stainless Steel Sea Pump with 2 Groove Pulley, 1-/4” NPT Center Inlet/Outlet
Your Price:
$1,099.99

2 Stage Stainless Steel Sea Pump with 2 Groove Pulley, 1-/4" NPT Center Inlet/Outlet

625-4951

2 Stage Stainless Steel Sea Pump with 2 Groove Pulley, 1-/4” NPT Center Inlet/Outlet

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


2 Stage Stainless Steel Sea Pump with 2 Groove Pulley, 1-/4” NPT Center Inlet & Dual 1” NPT Outlets
Your Price:
$995.99

2 Stage Stainless Steel Sea Pump with 2 Groove Pulley, 1-1/4" NPT Center Inlet & Dual 1" NPT Outlets

625-4952

2 Stage Stainless Steel Sea Pump with 2 Groove Pulley, 1-/4” NPT Center Inlet & Dual 1” NPT Outlets

The dual stage Extreme Sea Pump is the next step in our line of high performance, high volume raw water pumps. Incorporating two individual impellers this pump will double the volume of water delivered to your engine or give you the choice of separate routing to individual engine components. Dual stage pumps are commonly found on high horsepower pleasure boat applications where a dual independent water pump for an an intercooler, exhaust system or oil coolers is advantageous.

Available in either: Billet Aluminum or Stainless Steel, this dual stage sea pump is the key to solving over heating problems.


3 Stage Aluminum  Sea Pump
Your Price:
$975.99

3 Stage Aluminum Sea Pump

625-4960

3 Stage Aluminum Sea Pump

Our 3 stage Extreme sea pump is unsurpassed in the marine industry and is the number one choice of the most recognized engine builders and offshore racers in the world today!

Designed to incorporate the same features and the single and dual stage pumps, the addition of one more impeller allows for maximum water flow to be passed through the engine while the third impeller is dedicated to cooling the intercooler only. Dyno testing has shown that dedicating an individual water flow thru the intercooler does indeed increase horsepower. The triple stage Extreme pump allows you to accomplish this without sacrificing valuable cooling water in the engine itself. This pump is custom configured to your individual needs.