160 seamanship secrets
- Th e largest is the fuel fi ll line. It leads to the deck fi ll.
- Th e smallest is the fuel vent line. It leads aft or abeam.
- Th e fuel supply line leads to the engine.
- Some engines require a fourth line to return surplus fuel from the
injectors to the fuel tank.
Check for leaks or crimped or cracked fuel lines. Inspect the doubled hose
clamps. Follow the main fuel line to the fuel shutoff valve. Th is valve shuts off
fuel supply to the engine in an emergency. Turn the valve to the off position
(perpendicular to fuel line) and then back in line. If it is frozen from corrosion,
spray some lubricant to get it working again.
First (primary) fuel fi lter (before start-up). Follow the fuel line to the
fi rst (primary) fi lter. Some primary fi lters have a clear separator bowl on
the lower part of the fi lter. Th is traps water and contaminants and has
a drain plug on the bottom. Shine a light through the bowl. If it’s dirty,
drain the water and contaminants. Th ere’s no easy way to check a solid,
non-separator-type primary fi lter. You’ll need to take a sample from the
tank to analyze fuel quality. Do this once a year or anytime you suspect
contaminated fuel.
Secondary fuel fi lter (before start-up). Continue to follow the fuel line
to the secondary fi lter. It oft en resides on the engine block near the fuel
injection pump. Check for fuel leaks, cracks in the fuel lines, or corroded
hose clamps.
Fuel injection pump (before start-up). Follow the fuel line from the
secondary fi lter to the fuel injection pump. Inspect the high-pressure fuel
lines that lead from the pump to the injectors on top of the engine. Look
for fuel seepage at the pump and at each injector. Use a fl ashlight to spot a
sheen of leaking fuel anywhere around the engine body.
Engine drip pan (before start-up, while underway, and aft er shutting down).
Any liquid or odor of diesel fuel indicates a possible fuel leak. Stick your
fi ngers into the liquid and rub them together. Oily water indicates oil or fuel.
Sniff your fi ngers. No odor indicates leaking lubricating oil or coolant fl uid.
Look around the engine body where the head of the engine joins the engine
SEA-CRET TIP
X The ideal fuel tank is designed with a beveled bottom that traps
water and contaminants. A drain plug allows you to drain off the
dirty fuel.