Replacing the Fuel Line on a 2011 Suzuki King Quad 400ASi 4X4 Auto

Shop parts for a 2011 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Preparation is the difference between a tidy repair and a fuel-soaked afternoon. The 2011 King Quad 400ASi carries fuel under pressure, so the tools you lay out and the way you set up the workspace matter every bit as much as how you handle the hose itself. Build the kit first, then take the machine apart.

Building the Kit Before You Touch the Machine

  • Nitrile or rubber gloves and safety glasses — pressurized fuel can spray rather than drip
  • A lidded fuel-rated container and a shallow drain pan for whatever comes out of the line
  • Replacement hose rated for fuel-injection pressure and matched to the original inside diameter, not general-purpose carburetor tubing
  • Fresh clamps suited to the fitting style on your machine, plus a quick-disconnect release tool if it uses locking couplers
  • Line-clamping pliers for pinching off a low-pressure section, since there is no petcock lever on this model
  • Sockets and a flat-blade screwdriver for the seat and plastic panels, a sharp razor blade, and a generous stack of clean rags

Now the workspace. Gasoline vapor is heavier than air and drifts downward, pooling along the floor where furnace pilots, water heater burners, and power strips happen to sit. That means a cracked window accomplishes nothing; you want the garage door fully open or the quad out in the driveway. Shut down anything with a standing flame, keep grinders and torches out of the area entirely, and clean up spills the instant they occur instead of letting them evaporate underfoot for hours.

How This King Quad Delivers Fuel

The 400ASi is fuel injected, and the small "i" is the detail that shapes this entire job. An electric pump sits inside the tank and pushes fuel under pressure to the throttle body injector, so there is no gravity petcock to shut off and the circuit holds residual pressure well after the key is off. Relieving that pressure is your first mechanical step. Fittings on this platform may be self-locking quick-connect couplers rather than plain barbs with clamps, and the fuel filter is integrated into the in-tank pump module instead of being serviceable on the visible hose. As a 4X4 chassis with the automatic CVT drivetrain, it also routes the line around the front differential housing, the front driveshaft, and the additional frame crossmembers four-wheel drive requires, so the run is tighter than on a two-wheel-drive quad and the factory retaining clips are there for a reason.

The Reason Fuel Hose Has a Shelf Life

Rubber gives up from both surfaces. On the outside, heat cycles from the engine and long exposure to air and sunlight pull the plasticizers out of the compound, so the hose stiffens, goes chalky, and eventually opens hairline cracks wherever it bends. Dry, arid climates speed that process because the surrounding air keeps wicking moisture out of the hose wall. On the inside, ethanol-blended pump fuel absorbs water and chemically degrades the liner, and fuel left standing during an idle stretch leaves gum and varnish behind at the fittings. Because this system is pressurized, the pump actively works against every one of those weak points, so a flaw that would only seep on a carbureted machine can weep steadily here.

Symptoms That Justify the Job

Watch for a gasoline smell near the tank that peaks right after shutdown while pressure is still held, a wet patch or dried stain on the skid plate or frame, fine crazing or a glassy hard section you can feel by pinching the hose, and a dust-caked ring at either fitting where fuel has seeped and dried. On the running side, expect bogging under load, a stumble on hard acceleration, or a lean condition at higher rpm. Keep in mind that a small pressure-side leak often atomizes and evaporates before it can pool, so no puddle is not the same as no problem.

Depressurizing and Getting the Old Hose Out

Pull the fuel pump fuse or relay, crank the engine briefly until it stalls or refuses to fire, then turn the key off and disconnect the battery negative cable. Remove the seat and the plastics so the tank and the hose run to the throttle body are fully exposed, and slide the drain pan underneath.

Lay a rag over the first fitting you open, because a depressurized hose still holds fuel. Walk worm-gear or spring clamps well back along the hose before disturbing the joint. On a quick-connect coupler, press the locking tabs squarely and pull straight off with no sideways prying, since aged plastic collars crack easily. Where the hose has varnished itself to a barb, twist a quarter turn to shear the bond, and if it still holds, slice it lengthwise with the razor and peel it away in halves rather than stressing the fitting. Photograph the routing through every clip and past the front driveline before the old piece is completely free.

Fitting the New Hose and Verifying Under Pressure

Cut the replacement to the original length exactly. Extra hose is not margin, it is a chafe point against the frame or a hot surface. Push each end fully onto its barb until it bottoms out, working completely dry — no grease, no oil, no silicone on a pressurized sealing surface, because any lubricant there gives fuel a path to creep out and lets the hose migrate off the barb. Thirty seconds in hot water softens a stiff end enough to seat by hand. Position new clamps just behind the raised bead at each fitting and tighten evenly. If the tank side uses a self-locking quick-connect, push until the collar clicks and then tug firmly to confirm it has latched; that joint takes no clamp.

Reinstall the pump fuse, Reconnect the battery, and cycle the key on and off several times without cranking. Each cycle runs the pump and loads the circuit while the surrounding area is still dry, which is the cleanest way to spot a poor seal. Then start the engine, wipe both fittings with a clean rag, and let it idle for several minutes while you watch. Finish with a short slow lap and one last inspection while everything is warm before the panels and seat go back on.

Related Shopping Categories

Shop Fuel Lines for a 2011 Suzuki King Quad 400ASi 4X4 AUTO ATV.

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Shop Petcocks for a 2011 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Shop Fuel Filters for a 2011 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Shop Fuel Stabilizer for a 2011 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your ATV's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.