How Your Fuel System Works

A diesel fuel system includes a handful of core components that must work together to deliver clean, pressurized fuel to your engine.

  • Fuel Tank: Stores diesel. Water, sludge, and microbial growth often collect at the bottom.
  • Fuel Lines: Carry fuel from the tank to the engine. These need to be airtight to avoid suction leaks.
  • Primary Filter: Removes water and larger particles before they reach the engine.
  • Engine Fuel Pump: Pulls fuel through the system and builds pressure.
  • Secondary Filter: Finer filtration just before fuel enters the injectors.

If any part is compromised, your engine performance suffers.

What It Does

Measures suction in your fuel line and shows when filters are clogging or air is leaking.

Why It Matters

Helps detect problems before they affect engine performance.

Quick Tip

Run the engine at idle and close the fuel valve. If the needle drops, you have a leak.

What It Does

Removes water, sludge, and microbes before they reach your engine.

Why It Matters

Polish while underway or during fill-ups when fuel is stirred up.

Quick Tip

Run the engine at idle and close the fuel valve. If the needle drops, you have a leak.

What It Does

Keeps you running safely if a filter clogs mid-trip.

Why It Matters

Polish while underway or during fill-ups when fuel is stirred up.

Quick Tip

With a Keenan system, switching filters is fast, clean, and doesn’t require tools.

What It Does

Alerts you before your filters clog.

Why It Matters

Allows you to use finer filters without risking damage to the lift pump.

Quick Tip

Finer filters mean better protection, and early warning makes them safe to use.

What It Does

Supports polishing, priming, and can serve as a backup to the engine’s fuel pump.

Why It Matters

Makes maintenance easier and adds a layer of engine protection.

Quick Tip

Use it to prime filters after service or to bleed the system if you run dry.

What It Does

Keeps you self-reliant in offshore or rough-sea situations.

Why It Matters

Being able to change filters yourself can prevent costly delays.

Quick Tip

Top-loading filters are tool-free, low-mess, and don’t require bleeding.

A Word From Andy

Many boaters rely on mechanics, but offshore you need to be able to troubleshoot and fix basic issues yourself. Changing a clogged filter in rough seas isn’t fun but it’s a skill every boater should have. That’s why we design systems with top-loading filters and remote alerts so you're never caught off guard or unprepared.

“You don’t know what’s going into your tank until it’s already there. That’s why I always polish while fueling. If there’s water, I want to catch it before it causes problems.” —Andy Keenan, Founder