JLM MARINE Fuel Pump for Johnson & Evinrude 20-30 HP — Model 0438555, 28-Spline Direct-Fit

If your older Johnson or Evinrude outboard is sputtering, hard to start, or losing power under load, a worn or failed fuel pump is a common cause. This JLM MARINE 438555 pump (also referenced as 0438555) is manufactured to match the original equipment fitment for many 1990–2000-era engines and replaces multiple legacy part numbers so you can get back on the water without guessing which component you need.

Will this pump fit my Johnson or Evinrude outboard?

Compatibility covers a defined set of two-stroke outboards in the 20–30 horsepower range and aligns with the OEM mounting and splined shaft dimensions. Confirming model year and engine serial numbers before purchase prevents mismatches.

• Fits Johnson/Evinrude 20HP, 25HP, and 30HP outboards
• Designed for engines manufactured roughly between 1990 and 2000
• Direct replacement for part numbers: Johnson/Evinrude 438555, 433386, 777764
• Interchangeable with Sierra 18-7353 and Mallory 9-35353

How does this pump improve engine performance?

By restoring steady fuel pressure and consistent flow, the pump helps eliminate misfires, loss of acceleration, and rough idling caused by fuel delivery problems. It's engineered to reproduce the factory flow characteristics so carburetion and ignition timing remain stable under load.

• Delivers consistent fuel supply to carburetors
• Helps reduce hard-start and stalling issues
• Maintains proper engine response under throttle changes
• Engineered to match original flow spec for correct tuning

What should I know about installation and fitment details?

The pump features the common 28-spline drive used on the specified outboards, so installation is typically straightforward for anyone familiar with small engine maintenance. Basic hand tools and a short block-down service window are usually all that's required, but inspect gaskets and fuel lines while you service the unit.

• 28-spline shaft designed to match OEM drives
• Direct bolt-on replacement—no modification expected
• Replace mounting gasket and check fuel hose condition during install
• Suitable for routine DIY or professional marine mechanic replacement

How durable and reliable is the JLM MARINE 0438555 pump?

This replacement is built to meet the demands of marine use, with materials and tolerances chosen to resist corrosion and wear typical in outboard fuel systems. While it restores original functionality, lifespan depends on fuel quality, maintenance, and operating conditions.

• Constructed to withstand marine fuel system conditions
• Replaces multiple legacy part numbers for proven compatibility
• Performance relies on clean fuel and correct installation
• Regular inspection of pump and fuel lines extends service life

Who is this for: Boat owners and technicians who operate Johnson or Evinrude 20–30 HP outboards from the 1990s era and need a reliable, direct replacement fuel pump. It’s especially useful for restoring performance on older two-stroke outboards, performing scheduled maintenance, or addressing fuel-delivery faults without modifying the engine.