Replacing the Fuel Hose on Your 2017 Kymco MXU 150X
Shop parts for a 2017 Kymco MXU 150X ATV.
A gasoline smell in the shed is how most owners find this problem. You walk in, notice the odor is stronger than usual, and eventually trace it to a damp section of rubber between the tank and the carburetor. On a 2017 MXU 150X that is a straightforward fix. This is a carbureted, gravity-fed machine, so there is no fuel pressure to bleed off and no injector rail to open. Shut the flow, drain what sits downstream, and replace the hose.
The Symptoms That Send Owners Looking
Fuel line failure builds slowly, and there is almost always a warning period before anything strands you. Run your fingers along the entire length of the hose. Good rubber compresses under a pinch and springs back; a failing line feels rigid, or holds the crease you just put in it. Inspect both barbs closely, because seepage nearly always starts at a connection, and dried fuel leaves a telltale ring of caked dust behind.
Then watch how the engine behaves. A hose that has swollen internally or begun to collapse still supplies enough fuel to idle cleanly, which is exactly why the problem hides. Under load it cannot keep the float bowl filled, and the 149cc single starts bogging on climbs, hesitating when you open the throttle, or acting like the tank is nearly empty when it is not. Combine that with visible cracking, a persistent fuel odor, or a spot of gasoline on the floor and you have all the diagnosis you need.
Getting Set Up for the Job
Assemble everything before the first fitting comes loose:
- Rubber or nitrile gloves plus eye protection
- A fuel-rated container to catch what you drain
- Replacement hose in the original inside diameter, rated for gasoline service
- New clamps sized to the hose, with a spare or two on hand
- Line-clamping pliers, which you will need if your tank valve is vacuum-operated rather than a manual lever
- Screwdrivers, pliers, a socket set, clear tubing for the float bowl drain, a razor knife, and rags
Gasoline vapor behaves differently than most people assume. It is heavier than air, so it sinks and creeps along the floor, which means ventilation matters most at ground level. Work outdoors when you can. In a garage, open the main door fully, put a fan on the floor moving air out, and shut off anything with a standing pilot flame. Disconnect the battery while the line is open, keep work lights cool and distant, and dry fuel-soaked rags outside instead of sealing them up.
What Wears Fuel Line Out
The rubber loses its flexibility from the outside in. Plasticizers that keep it soft slowly leave the material, and the wall becomes hard and brittle. Repeated heating and cooling from the nearby engine speeds that along, and once flexibility is gone, routine vibration and frame flex crack the surface. In dry climates the hose gives up moisture to the surrounding air and hardens noticeably faster.
At the same time, ethanol-blended fuel degrades the inner liner. E10 attracts water vapor, and the mixture softens the hose interior until it swells and starts shedding fine particles toward the carburetor. Leave that fuel standing in the system for months at a stretch and gum and varnish form on top of the chemical damage, restricting flow through the barbs and cementing the hose in place. A machine that gets ridden regularly with fresh fuel simply lasts longer at this one job.
Working the Old Hose Free
Close the tank valve if yours has a lever. If instead you find a small vacuum hose running to the valve body and no lever to turn, clamp the fuel line shut with pliers, since there is no manual shutoff on that arrangement. Disconnect the battery negative cable, lift the seat, and remove enough plastic to see the full hose run in one view. Photograph the routing and every clip before anything comes apart.
Empty the downstream fuel through the carburetor's float bowl drain. Fit clear tubing over the drain nipple, run it into your container, and open the drain screw until the bowl runs dry. Slide a pan under the tank fitting as well and lay a rag across it, because a valved-off line still holds gasoline that will run out the moment you pull the hose.
Move both clamps well back along the hose before disturbing either joint. Old rubber sticks to brass with dried varnish, so rotate the hose gently to break the bond instead of hauling on it. When a section will not release, split it lengthwise with the razor and peel it off. The petcock spigot and the carburetor inlet are thin-walled, and neither is worth breaking to save thirty seconds. Being a two-wheel-drive quad, the MXU 150X gives you a short, direct hose path with no front differential hardware to navigate around, which makes access easier than on a four-wheel-drive machine.
Fitting the New Line
Match the new hose to the length of the old one exactly. Slack sags into a frame tube and abrades through over time, and a piece cut too short puts constant tension on both barbs as the engine rocks. Push each end on dry until it bottoms past the raised bead. Do not use grease, oil, or spray lubricant to ease installation. Any film on the sealing surface gives pressurized or gravity-fed fuel a route to migrate out from under the hose, and no amount of clamp torque fixes that. A brief soak of the hose end in hot water makes stiff rubber slide on unaided.
Seat the clamps just behind the bead on each fitting and tighten them evenly until the hose no longer rotates by hand. Overtightening a worm-gear clamp bites into the wall and creates the next leak, so stop when it is snug. Return the line to its factory clips, verify clearance from exhaust heat and steering components, and close the float bowl drain screw.
Confirming the Repair Holds
Reconnect the battery and restore fuel flow, then step back for a minute or two. Gravity refills the line and the float bowl, and inspecting a static system is the surest way to catch a slow weep before it becomes a puddle. Wipe both joints clean, feel around each with a dry finger, and check a rag laid underneath for spotting.
With everything dry, start the engine and look again while it idles and shakes. Blip the throttle several times, ride a short low-speed loop, then shut down and check both fittings one final time before the bodywork goes back on. Since this machine runs a carburetor, its fuel filter is an inline component you can reach rather than a unit built into a pump inside the tank, as injected machines use. The system is already drained, so replacing that filter now is nearly free effort and leaves you with a completely fresh path from tank to carburetor.
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Shop Fuel Stabilizer for a 2017 Kymco MXU 150X 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.