Fuel Line Replacement on the 2020 Sherco 300 SEF FACTORY

Shop parts for a 2020 Sherco 300 SEF FACTORY Dirt Bike.

Rubber fuel hose is among the cheapest parts on a 2020 Sherco 300 SEF FACTORY and one of the few that can end a ride outright. It hardens, cracks, and weeps fuel where you cannot see it, eventually either starving the engine or putting gasoline somewhere it should never be. Swapping it needs no specialty tools and no shop time.

Understanding How the Line Deteriorates

Two things degrade a fuel line: time, and what sits inside it. Rubber loses flexibility as it ages, and a hose that spent eight years on a 2020 Sherco 300 SEF FACTORY has been hardening the whole time, ridden or parked. Hardened rubber cannot absorb vibration, so it cracks where it stretches over a fitting. Ethanol-blended gasoline is the other half — fuel sitting unused for months attracts moisture and breaks down, which is rough on hose material and leaves varnish behind. Add a dry climate baking out what flexibility remains, and a line that looked fine last season can be brittle by spring.

What Fuel Injection Changes Here

Your 2020 Sherco 300 SEF FACTORY uses fuel injection rather than a carburetor, which changes the job in one meaningful way: there is no petcock to shut off. Fuel sits under pressure from an in-tank pump and feeds the throttle body through a line that often ends in a quick-connect fitting rather than a barbed spigot with a clamp.

Red Flags During a Pre-Ride Look

Most failing fuel lines warn you before letting go. The warnings are easy to dismiss, so it helps to know what you are looking at when you walk up to your 2020 Sherco 300 SEF FACTORY.

  • A puddle or damp patch underneath. Even a slow weep leaves evidence, usually below the tank or carburetor.
  • A strong fuel smell in the garage. Odor lingering a day after parking is not normal.
  • Visible cracking. Bend the hose gently; fine cracks that open under flex mean the rubber is done.
  • A hose that feels hard or glazed. Healthy line is soft and slightly tacky.
  • Bogging or running lean. A collapsed or deteriorated line restricts flow, and the engine acts like the tank is nearly empty.

Getting Set Up Before You Start

This is a low-cost job, and most of the preparation is about containing fuel rather than turning wrenches.

  • Replacement fuel line rated for injection pressure and sized for your 2020 Sherco 300 SEF FACTORY. Low-pressure carburetor hose is not a substitute.
  • Line-clamping pliers. With no petcock on the 300 SEF FACTORY, these are how you stop the tank siphoning while the line is open.
  • New clamps or the correct quick-connect fitting, depending on your connections. Some injected models need no clamp at all.
  • Nitrile gloves and eye protection. Pressurized fuel can spray when a connector releases.
  • A fuel-safe drain container and a funnel.
  • Shop rags positioned at the fitting before you break it loose.

Before the first fitting comes loose, handle the safety side. Gasoline vapor pools low and finds ignition sources you would never consider, including pilot lights across the room. Ventilate properly, keep fuel in a closed container, wear eye protection, and never open the system on a hot engine.

Draining Down and Pulling the Line

Because the 300 SEF FACTORY has no fuel valve, your first move is to pinch the line off. Line-clamping pliers squeeze the hose shut without damaging it, and that is what stands between you and a tank draining onto the floor. Position them on a straight section, not on a bend or a fitting.

Next, deal with residual pressure. An injected system holds pressure after shutdown, so cover the connection with a rag, wear eye protection, and ease the fitting apart rather than popping it loose.

Then separate the connections. If your 2020 Sherco 300 SEF FACTORY uses a push-to-connect coupler, find the release — usually a plastic tab you compress, a collar you pull back, or a hairpin clip you slide out. Depress it fully and pull the halves apart in line with the fitting. If instead you find a barb and clamp, retract the clamp with pliers or a driver, rotate the hose to break its grip on the metal, and work it off. Hardened line is best slit with a blade.

Installing the Replacement Hose

Cut the new pressure-rated hose to match the original length exactly. On an injected 300 SEF FACTORY the routing is often tighter than on a carbureted bike, and extra length has nowhere useful to go. Square, clean cuts matter more here because the joint seals against pump pressure rather than gravity.

Seat the tank-side connection first. If your 2020 Sherco 300 SEF FACTORY uses a quick-connect coupler, push the halves together firmly until the lock clicks, then confirm engagement by pulling lightly — a coupler that is not latched will separate under pressure. These fittings are self-locking and need no clamp at all. Where a barbed fitting is used instead, drive the hose fully onto the barb.

Leave lubricant out of it. No grease, no oil, nothing on the fitting or hose end, whatever the connection type. It degrades the seal, and on a quick-connect it can interfere with the locking mechanism. Finish at the throttle body end, verify the routing is clear of heat and moving parts, and install clamps only where the design calls for them.

Wrapping Up and Checking Your Work

Remove the clamping pliers and pressurize the system before starting the bike. Turning the key on for a moment runs the pump on your 2020 Sherco 300 SEF FACTORY and loads the new joint with real pressure; that is your first and most informative test. Inspect both connections with good light immediately after.

Then run it. Bring the engine to temperature and check the fittings again, paying attention to any quick-connect coupler. Those either latch fully or they do not, and a partially engaged connector can separate under pressure with the engine running. Confirm the retaining clip is home and the joint is bone dry.

One thing to know on the 300 SEF FACTORY: because injected models typically house the fuel filter inside the tank with the pump, the line you replaced has no serviceable filter on it. Finish by disposing of the drained fuel responsibly and rechecking your work after a ride. Broader background on fuel line care and why lines fail during storage is covered in our general guide to replacing a dirt bike fuel line.

Related Shopping Categories

Shop Fuel Lines for a 2020 Sherco 300 SEF FACTORY Dirt Bike.

Shop Fuel Line Clamps for a 2020 Sherco 300 SEF FACTORY Dirt Bike.

Shop Petcocks for a 2020 Sherco 300 SEF FACTORY Dirt Bike.

Shop Fuel Filters for a 2020 Sherco 300 SEF FACTORY Dirt Bike.

Shop Fuel Stabilizer for a 2020 Sherco 300 SEF FACTORY Dirt Bike.

Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your dirt bike'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.