Changing the Fuel Hose on a 2004 Honda TRX450 Foreman 4x4

Shop parts for a 2004 Honda TRX450 Foreman 4X4 ATV.

Age is the enemy of fuel hose, and the 2004 TRX450 Foreman 4x4 closed out its production run long enough ago that the original rubber has almost certainly gone hard. Understanding why that happens is the fastest way to know whether yours needs attention. This Foreman is carbureted and gravity fed: a manual valve at the tank, a short hose, and a carburetor inlet, with no pump and no pressure anywhere in the circuit. It is a simple system, which is exactly why a single degraded hose can cause running problems that look far more complicated.

The Slow Death of Rubber Fuel Line

New fuel hose is soft because it is loaded with plasticizers. Those compounds gradually migrate out of the wall over years of heat cycles, and the rubber left behind is stiffer, slightly shrunken, and much less willing to flex. Once that happens, every vibration and every temperature swing works micro fractures into the surface, usually starting where the hose bends over a fitting.

Climate has a real effect on the pace. In dry regions the surrounding air pulls residual moisture out of the hose wall, hardening the outer skin faster than the same part would age in humid country, and the result is that chalky, crazed appearance familiar to anyone who works on older machines. Ethanol–blended fuel finishes the job from the inside, carrying moisture into the line and slowly breaking down the inner liner. Gas that sits unused for months leaves gum that both bonds the hose to the barbs and flakes loose toward the carburetor jets.

Telltale Signs on Your Foreman

These are the symptoms that should send you looking:

  • Fuel pooled on the skid plate or floor, or a wet streak running down the engine
  • A gasoline smell that greets you when you open the shed door
  • Cracks, a chalky bloom, or a section that feels rigid when squeezed between your fingers
  • Bogging under load, a hesitation just off idle, or lean surging that mimics a nearly empty tank
  • Dried fuel residue at a barb, visible as a dark dust collar around the fitting

Because the tank feeds downhill on this model, a leak between the valve and the carburetor can drain fuel while the machine simply sits, so treat any of these as urgent rather than seasonal.

Verifying the System and the Layout

Find the petcock at the base of the tank on the left side, marked OFF, ON, and RES. That valve is your only shutoff, and it makes the whole job possible without draining the tank. The contrast with a fuel–injected utility quad is worth knowing: those machines have no petcock, run an electric pump inside the tank, hold pressure in the supply hose that must be relieved before anything is opened, and place the fuel filter inside the pump assembly rather than out on the line. None of that applies to your 2004 Foreman.

This is a 4x4, so the front differential and its driveshaft take up space along the lower frame and the fuel hose is clipped to hold it clear of that hardware as well as exhaust heat. A two–wheel–drive machine has a more open path through the same area. Photograph the routing and every clip before removal.

Assembling Tools and Managing Fumes

Set out the following:

  • Gloves in nitrile or rubber, plus eye protection
  • A drain pan and a sealed fuel–rated container for the gas you recover
  • Gasoline–rated hose in the correct inside diameter
  • Replacement clamps in the style your machine uses
  • Screwdriver, needle–nose pliers, a pick, a socket set, and a stack of clean rags

Work in open air. Gasoline vapor is denser than air and drifts along the floor, which puts it at the level of water heaters, shop heaters, and anything else with a flame or a spark down low. Keep the recovery container capped between pours, avoid any grinding or hot work in the same building, and remove the fuel–soaked rags from the enclosed space when you are finished.

Taking the Old Hose Out

Turn the valve to OFF. Remove the seat and whatever fender section or tank cover stands between you and the hose run. Slide the pan under the carburetor, open the float bowl drain screw, and let the bowl and line empty through the overflow tube, then retighten the screw. Now the hose can come off with almost nothing left in it.

Move each clamp back along the hose, well clear of the barb. Break the hose loose with a twisting motion instead of a straight pull, because varnish will have it stuck fast. Anything that still refuses gets slit lengthwise with a razor and peeled off, which spares the petcock spigot and the carburetor inlet. Note which hose is the tank vent so it does not get confused with the fuel line during reassembly, and clean old rubber residue off both barbs.

Fitting the Replacement and Confirming No Leaks

Cut the new hose to the original length. Too long and it sags toward the front driveline; too short and it pulls at both ends every time the engine shifts on its mounts. Push each end on dry, fully seated against the shoulder, with nothing on the barb to help it slide. Grease, oil, and silicone all create leak paths and cannot be undone once applied, so use a few seconds in hot water instead. Set the clamps behind the raised bead at each fitting, tighten evenly, and thread the hose back into every original clip so it clears the header and the front drive components.

Open the petcock to ON and watch both joints for a solid minute, wiping and rechecking with a dry rag. Repeat on RES, which draws from lower in the tank. Start the engine and inspect once more at idle while the hose warms to temperature, and reinstall the plastics only after everything stays dry. Continued bogging after a leak–free install usually points to debris the old hose already sent downstream, which makes the float bowl and jets your next stop.

Related Shopping Categories

Shop Fuel Lines for a 2004 Honda TRX450 Foreman 4X4 ATV.

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Shop Petcocks for a 2004 Honda TRX450 Foreman 4X4 ATV.

Shop Fuel Filters for a 2004 Honda TRX450 Foreman 4X4 ATV.

Shop Fuel Stabilizer for a 2004 Honda TRX450 Foreman 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.