Fuel Line Replacement on the 2008 Polaris Sportsman 800 EFI 4x4
Shop parts for a 2008 Polaris Sportsman 800 EFI 4X4 ATV.
Pop the seat off a 2008 Sportsman 800 EFI 4x4 and the first thing worth confirming is what kind of fuel system you are about to open. The letters in the model name settle it — this is an electronically fuel injected twin, so there is no petcock lever hiding under the tank and no gravity feed to simply switch off. A pump submerged in the tank pushes fuel down the supply hose under real pressure, and that hose stays charged even after the key comes out. Understanding that before a wrench touches anything keeps a routine hose swap from turning into a sprayed garage floor.
How the Supply Circuit Is Laid Out
On this generation of the 800 twin, fuel leaves the in–tank pump module and travels forward and down to the throttle body assembly feeding the injectors. Because the 800 is a full 4x4 machine with an on–demand front driveline, the hose has to clear front differential hardware, the front prop shaft tunnel, and a couple of extra frame crossmembers that a simple two–wheel–drive quad never carries. That means more clips, more guides, and a slightly longer run to trace. Follow the whole length with a flashlight and note every retaining clip before you loosen anything.
The Slow Death of a Rubber Hose
Fuel hose does not usually fail all at once. It ages from both directions at the same time. On the outside, engine heat cycles and years of ultraviolet exposure bake the plasticizers out of the rubber until a hose that used to squish between your fingers feels like a piece of conduit. Riders in dry, low–humidity country watch this happen faster, since arid air pulls moisture from the hose wall and speeds the hardening along. Once the material goes glassy, frame flex over washboard trail opens hairline cracks that grow with every mile.
From the inside, ethanol–blended pump gas does its own work. Alcohol attracts water, and a Sportsman that sits through a long off season with E10 in the system slowly gives up its inner liner to that mixture. The hose softens internally while stiffening externally, and small flakes of degraded liner head straight for the injectors. On a machine this far past its build date, calendar age alone justifies a fresh line even if nothing looks wrong yet.
Symptoms Worth Chasing Down
- A fuel stain or small puddle on the skid plate or the floor where the quad was parked overnight
- Raw gasoline smell around the tank area, strongest in the first minutes after shutdown while pressure is still held
- Visible surface checking, a chalky gray cast, or hard spots you can feel by pinching the hose along its length
- The engine bogging under throttle, stumbling as rpm climbs, or acting starved when the tank is clearly not empty
- A dust–caked ring around a fitting, which is the classic fingerprint of fuel seeping and drying repeatedly
Keep in mind that a pressure–side pinhole on an injected machine often never drips. Fuel atomizes as it escapes and evaporates before it reaches the ground, so your nose frequently finds the problem before your eyes do.
Gathering Tools and Making the Space Safe
Set everything out first so you are never holding an open line while hunting for a tool:
- Nitrile or rubber gloves, since gasoline strips skin oils fast
- An approved sealed container plus a shallow catch pan for spilled fuel
- Replacement hose rated for fuel injection pressure in the original inside diameter, not general purpose carburetor tubing
- Fresh clamps matched to the fitting style you find, and a quick–connect release tool if the tank end uses a locking coupler
- Line–clamping pliers to pinch off any low pressure section, because this model gives you no valve to close
- Sharp razor knife, small flat blade screwdriver, socket set, and a stack of rags
Do this work outside or with the door fully open. Gasoline vapor is heavier than air and settles at floor level, so ventilation low in the space matters far more than a cracked window overhead. No grinders, no heaters, no smoking, and nothing running that can throw a spark near the floor.
Getting the Old Line Out
Bleed the pressure down before anything else. Pull the fuel pump fuse or relay, crank the 800 briefly until it dies from starvation, switch the key off, then disconnect the battery negative cable. Remove the seat and the front rack plastics to expose the tank neck and the top of the pump module. Slide your pan into position and drape a rag over the first fitting so residual fuel goes into cloth instead of down the frame rail.
Worm gear or spring clamps should be walked back along the hose before you disturb the joint. Quick–connect couplers need the locking tabs squeezed squarely and the fitting pulled straight off — never levered sideways, since aged plastic collars snap under that load. If varnish has glued the hose to a barb, slit it lengthwise with the razor and peel it away rather than twisting hard on a plastic spigot. Photograph the routing while the old hose is still in its clips.
Fitting the New Hose
Cut the replacement to the same length as the piece you removed. Extra hose sags into the front driveline or chafes on a frame edge, and a short piece pulls on its fittings every time the chassis moves. Push each end fully home until it bottoms against the shoulder of the barb. Work it on completely dry — no grease, no oil, no silicone spray, because any lubricant on a sealing surface gives pressurized fuel a path to creep out under it. A dip in hot water softens a stubborn end enough to slide on unassisted.
Set new clamps just behind the raised bead of each fitting and tighten evenly, snug rather than crushed. Where the tank side uses a self–locking quick–connect, push until the collar clicks and then pull firmly to confirm the latch caught. That style needs no clamp at all. Return the hose to every original clip so it stays clear of hot exhaust and the front differential.
Proving the Repair
Reinstall the fuse, Reconnect the battery, and cycle the key on and off four or five times without cranking. Each cycle runs the pump and charges the circuit, letting you study both joints while the surrounding metal is still dry. Wipe everything clean, then fire the engine and watch the fittings at idle for several minutes with a fresh rag in hand. Only when the area stays completely dry should the plastics go back on.
One last point specific to the EFI Sportsman: the fuel filter lives inside the tank as part of the pump assembly rather than sitting inline where you can reach it. New hose solves a leaking or collapsing hose problem, but it does nothing for a plugged filter screen. If the 800 still stumbles under load after a clean install, the in–tank module is the next thing to pull.
Related Shopping Categories
Shop Fuel Lines for a 2008 Polaris Sportsman 800 EFI 4X4 ATV.
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Shop Fuel Filters for a 2008 Polaris Sportsman 800 EFI 4X4 ATV.
Shop Fuel Stabilizer for a 2008 Polaris Sportsman 800 EFI 4X4 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.