How to Change the Fuel Line on a 2017 KingQuad 400FSi 4x4
Shop parts for a 2017 Suzuki King Quad 400FSi 4X4 AUTO ATV.
Getting the Old Hose Off the Machine
The removal is the part that decides how the rest of the afternoon goes, so start there mentally. On the 2017 KingQuad 400FSi you begin by relieving fuel pressure, because this is an injected machine with a pump inside the tank instead of a petcock beneath it. Pull the fuel pump fuse or relay from the fuse block, crank the engine until it stalls from starvation, switch the key off, then disconnect the battery negative cable. Only after that sequence do you touch a fitting.
Remove the seat and whatever bodywork covers the tank outlet and the hose run heading to the throttle body. Slide a catch pan underneath and lay a rag over the joint you plan to open, since a depressurized line still holds fuel that will run out the moment it is free. Push worm gear or spring clamps well back along the hose before breaking anything loose. If the tank end uses a locking quick-connect, squeeze both release tabs evenly and pull the coupler straight off without prying to one side, because plastic collars grow brittle with age and crack under leverage. Twist a bonded hose gently to break the varnish at the barb, and if it refuses to release, slit it lengthwise with a razor and peel it away rather than damaging a fitting you intend to keep.
The Fuel System You Are Working On
Confirming the layout keeps you from applying the wrong procedure. The FSi designation identifies the fuel-injected KingQuad 400, mated to the five speed semi-automatic gearbox and 4x4 drive. Injection means no fuel valve, no gravity feed, and a supply hose that remains pressurized after the key comes off. Line clamping pliers stand in for the shutoff the machine does not have.
The 4x4 hardware influences routing. Front differential components, a driveshaft, and additional frame bracing crowd the space the hose has to navigate, so the factory clips and clearance points do real work holding the line clear of exhaust heat and rotating parts. That is worth a few photographs before the old hose leaves the chassis, because rebuilding the original path is what keeps the new hose alive.
Installing the Replacement
Measure the piece you removed and cut the new hose to match. Extra length is not a margin of safety, it is a chafe point against a frame tube or a snag at full steering lock, and a piece cut short puts constant tension on both fittings. Work each end fully onto its barb until it seats against the shoulder, and keep the entire installation dry. Grease, oil, silicone spray, and sealant are all forbidden here, because lubricant on a sealing surface hands pressurized fuel a path out from under the clamp. If a hose end resists, dip it briefly in hot water to soften the rubber and push it on unaided.
Position the clamps just behind the raised bead on each fitting and tighten them evenly, firm rather than crushed into the hose wall. A self-locking quick-connect requires no clamp at all and is finished once it clicks and survives a hard tug. Then thread the hose back through every original clip and confirm real clearance from the exhaust and the front driveline before the plastics go back on.
Why the Line Failed in the First Place
Rubber fuel hose ages out rather than wearing out. Plasticizers give it flexibility, and they slowly migrate out of the hose wall until the material behaves like thin brittle plastic. Heat cycles from the air and oil cooled single speed that decline, and the vibration and chassis flex a working utility quad absorbs across rough ground deepen every hairline crack that forms.
The setting dictates the pace. Low humidity climates pull moisture out of the hose and harden it from the outer surface inward, so a quad kept in dry country can need hose years before an owner would expect. Ethanol blended pump gas works from the inside instead, absorbing water and degrading the inner liner during any period the fuel sits unused. Both processes can be underway at once, producing a hose that looks acceptable while quietly sending material toward the injector.
Symptoms Worth a Second Look
- Persistent gasoline smell around the quad, strongest in the minutes after shutdown
- Fuel drips, stains, or a damp patch on the skid plate or beneath the frame
- Surface cracks that open when the hose is flexed, or a stiff and chalky texture
- Dust caked onto a wet ring at either fitting, the usual sign of a slow seep
- Bogging under load, hesitation off idle, or lean surging as though fuel were running out
A pressurized leak frequently atomizes and evaporates instead of dripping, so an odor with nothing on the floor still deserves investigation.
Supplies and Handling Gasoline Sensibly
You want gloves and eye protection, hose rated for injection pressure in the correct inside diameter, new clamps in the right style, line clamping pliers, a quick-connect release tool if a locking coupler is present, an approved sealed fuel container, a shallow catch pan, a socket set, a small flat blade screwdriver, a razor knife, and clean rags. Lay it all out first so you are never holding an open line while looking for something.
The real hazard is vapor rather than liquid. Gasoline fumes are heavier than air, so they settle across the floor and drift toward water heater pilots, propane heaters, and battery charger contacts. Work outdoors or with the overhead door fully open, get low level air moving through the space, and shut off anything with a flame or a spark before you begin. Keep an extinguisher within reach, cap the fuel container between pours, and never send drained fuel into a shop drain.
Verification and One Final Detail
Reinstall the pump fuse, Reconnect the battery, and cycle the key on and off several times without cranking so the pump pressurizes the line while all the joints are still dry. Wipe each connection with a clean light rag so the smallest bead of fuel becomes obvious. Start the engine and inspect at idle, then check again after a few minutes of running plus a slow lap.
Last, keep the filter location in mind. On the injected KingQuad 400FSi the fuel filter is part of the in-tank pump assembly rather than an inline piece on the hose you just replaced, so fresh line will not resolve a restriction there. If the machine still runs starved once the connections are dry and secure, that in-tank assembly is where to look next.
Related Shopping Categories
Shop Fuel Lines for a 2017 Suzuki King Quad 400FSi 4X4 AUTO ATV.
Shop Fuel Line Clamps for a 2017 Suzuki King Quad 400FSi 4X4 AUTO ATV.
Shop Petcocks for a 2017 Suzuki King Quad 400FSi 4X4 AUTO ATV.
Shop Fuel Filters for a 2017 Suzuki King Quad 400FSi 4X4 AUTO ATV.
Shop Fuel Stabilizer for a 2017 Suzuki King Quad 400FSi 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.