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.
  • Fuel Lines: Carry fuel from the tank to the engine. These need to be airtight to avoid suction leaks.
  • Primary Filter: First line of defense. Removes water and larger particles before they reach the engine.
  • Engine Fuel Pump: Pulls fuel through the system and builds pressure.
  • Secondary Filter: Last line of defense before fuel enters the injectors.

If any part is compromised, your engine performance suffers.

What a Vacuum Gauge Helps

Measures the amount of suction to draw the fuel through the filter element. It also can help determine if you have an air leak.

Why It Matters

Helps easily detect problems with a glance before they affect engine performance. It also helps you eliminate unnecessary filter changes by show flow is OK.

Quick Tip

To test the system for air leaks. Operate the engine at idle and shut off the fuel inlet valve on the  filter, (this will simulate a filter clogging) monitor the vacuum gauge needle. When it reaches 10 inHg shut off the engine. The needle should stay at the setting when you shut off the engine. If the needle starts dropping it is a sign of an air leak.

What It Does

Removes water, microbes and contaminants in the stored fuel.

Why It Matters

Lets the operator know the condition of the fuel in the tank. ensures clean fuel for engine reliability.

Quick Tip

Fuel polishing is best done just
after returning from a trip or when you are adding more fuel to the tanks while the fuel is agitated allowing the contaminants to be suspended in the fuel. This will allow for the filter element to do its job and collect the debris.

What It Does

Allows the operator to switch filters keeping the engine operating.

Why It Matters

Keeps the vessel moving while dirty filter is changed.

Quick Tip

Using the internal priming system allows the operator to replace and prime the dirty
filter very quickly..

What It Does

Warns the operator the online filter is starting to clog or water is detected.

Why It Matters

knowing
of a problem in advance keeps the vessel in operation.

Quick Tip

Early warning allows the use of finer filter for cleaner fuel delivery without
harming the engine lift pump.

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