Full Power Plus Johnson/Evinrude 40–50HP Water Pump Repair Kit (1989–2005) — Complete Impeller & Seal Rebuild

Full Power Plus water pump repair kit replaces worn impellers and seals on Johnson/Evinrude 40–50 HP 2-stroke outboards (1989–2005) to restore reliable cooling flow.

This complete replacement kit is built to match OEM-equivalent components for Johnson and Evinrude outboards and fits the common Sierra Mallory part references including 18-3454 and 438592. The kit bundles the rubber impeller, gaskets, housing, seals, O-rings, screws and other hardware so you get everything needed for a single pump rebuild. Materials combine modern neoprene for the impeller with durable metal alloys for housings and plates to resist wear in freshwater and light saltwater use.

What parts are included and which original part numbers does it replace?

The kit contains a full set of water pump components so you won’t need to source additional pieces for a standard rebuild. It is designed as a direct replacement for several commonly referenced OEM and aftermarket numbers.

• Included: impeller, seal, grommet, face plate, gasket, impeller key, pump housing, cup, screws, and O-rings.
• Replaces: 438592, 433548, 433549, 777805, 0433548, 0433549, 0777805, 0438592 and Sierra 18-3454, 18-3394; Mallory 9-48209 equivalents.
• Fits: Johnson/Evinrude 40, 45, 48, 50 HP 2-stroke outboards from 1989–2005.

How durable and reliable are the materials in the kit?

Components are manufactured from long-wearing alloys and modern neoprene compounds intended to extend service life compared with older stock parts. The neoprene impeller resists deformation while the metal housing and face plate resist galling and corrosion when maintained properly.

• Impeller: modern neoprene for flexibility and heat resistance.
• Housing and plate: corrosion-resistant metal alloy construction.
• Seals and O-rings: sized to prevent leaks under typical operating pressures.

How simple is installation and what tools will I need?

Installation follows standard water pump rebuild steps and is suitable for DIY mechanics with basic marine tools. If you are comfortable removing the lower unit and following torque and alignment notes, this kit includes everything needed; professional installation is recommended if you’re unfamiliar with outboard maintenance.

• Common tools: socket set, screwdrivers, torque wrench, gearcase drain tools.
• Procedure basics: remove lower unit, disassemble old pump, replace parts, reassemble and torque to spec.
• Included hardware eliminates the need to buy extra screws or gaskets for a single rebuild.

Will this kit work for my exact engine model year and symptoms to watch for?

The kit covers a range of 40–50 HP Johnson and Evinrude 2-stroke models from 1989 through 2005, but always verify part numbers or measure your pump before purchase. Signs your water pump needs replacement include engine overheating, low coolant flow, cavitation, or visible damage to the impeller blades.

• Check compatibility by matching existing part numbers or measuring impeller diameter and housing fit.
• Common symptoms: rising engine temp, engine revs drop under load, visible chopped impeller blades.
• Recommended maintenance: inspect annually or after prolonged idle/storage periods.

Who is this for: Boaters, marine technicians, and DIYers who own Johnson or Evinrude 40–50 HP 2-stroke outboards (model years 1989–2005) and want a single, complete pump rebuild kit that replaces popular Sierra and Mallory part numbers. If you need a full set of replacement components to restore cooling performance or perform scheduled lower-unit maintenance, this kit supplies the hardware and elastomers commonly required for a successful repair.