How to Replace the Fuel Line in a 2018 Sherco 300 SE FACTORY Dirt Bike

Swapping the Fuel Line on Your 2018 Sherco 300 SE FACTORY

Shop parts for a 2018 Sherco 300 SE FACTORY Dirt Bike.

If you have owned your 2018 Sherco 300 SE FACTORY more than a few seasons, the fuel line deserves a hard look. It is a wear item almost nobody thinks about until it fails, and the failure is rarely graceful. Replacing the hose costs a few dollars, and doing it early beats doing it trailside with a leaking tank.

Confirming the Fuel System on Your 2018 Sherco 300 SE FACTORY

Fuel delivery on the 2018 Sherco 300 SE FACTORY is carbureted, so the plumbing is about as simple as it gets on a two-stroke dirt bike — tank, petcock, hose, carburetor. That petcock is the most useful thing about this job. Turn it off and the fuel stops, which means no siphoning and no fighting gravity while you work.

What Actually Kills a Fuel Line

Rubber fuel line fails for reasons that have little to do with how hard you ride. Age drives it: the plasticizers keeping the hose flexible slowly migrate out, and pliable rubber turns stiff and glassy, so a small flex — bolting the tank down, rocking the bike onto a stand — opens a hairline crack. Dry, hot storage accelerates that, pulling volatiles out faster than a temperate garage would. Ethanol-blended pump fuel left sitting in the hose adds a second mechanism, attacking the inner wall and leaving gum that can flake into the fuel path on a 2018 Sherco 300 SE FACTORY.

How a Failing Line Announces Itself

Catching a bad line early is mostly about paying attention during routine checks. On a 2018 Sherco 300 SE FACTORY, these signals should send you looking at the hose.

• Wet spots on the frame or cases. Fuel evaporates fast, so look for residue rather than liquid.
• Fuel odor that will not clear. A leak too small to see is still large enough to smell.
• Hairline splits near the clamps. The clamped section takes the most stress and cracks first.
• Hose that holds its bend. If the line refuses to straighten, the rubber has hardened.
• Symptoms resembling a fueling fault. Bogging on hills or running lean with a full tank.

What to Have on the Bench

The parts list is short and the tool list shorter. Lay it out before breaking the first connection.

• Replacement fuel line in the correct inside diameter and length for your 2018 Sherco 300 SE FACTORY. Match the original rather than guessing — oversized line will not seal on the barb.
• New clamps. Spring clamps lose tension with age, and a small clamp kit costs very little.
• Nitrile or rubber gloves. Gasoline absorbs through skin.
• A fuel-safe drain container and a funnel if you plan to reuse the fuel.
• Pliers and a small flat screwdriver for spring and screw clamps respectively.
• Shop rags and eye protection.

One genuine safety note: gasoline vapor is heavier than air and travels along the floor toward anything that can ignite it. Work outdoors or with the door open, shut off any heater with a pilot light, keep the fuel container capped, and let a hot engine cool first.

Taking the Failed Hose Off

Shut the petcock off first. That single step keeps this job clean on a carbureted 300 SE FACTORY — with the valve closed, the tank stays full and the only fuel to manage is what is already past the valve.

Empty the carburetor next. Attach a length of clear hose to the float bowl drain nipple, direct it into your container, and open the drain screw. A minute later the bowl is dry and you can work without fuel running down your arm.

With the fuel handled, address the clamps at each end. Squeeze spring clamp tabs together with pliers and walk the clamp down the hose, or loosen a screw clamp with a driver. The hose is usually the hard part: years of heat cycling effectively glue it to the barb. Twist first to break the bond, then pull straight off. When a line is badly hardened, cutting it off with a razor blade is safer for the fitting than prying at it.

Routing and Securing the New Line

Measure the replacement against the old line before cutting. Matching the original length keeps routing correct on the 300 SE FACTORY, and a square cut gives the clamp a clean surface to seal against. Trim with a fresh blade rather than dull side cutters.

Slide the hose fully onto the tank-side fitting, past the barb and up against the shoulder. If the rubber resists, soften it in hot water; do not reach for lubricant. Grease or oil on a fuel fitting shows up later as a slow weep and can carry contamination into the carburetor.

Attach the carburetor end and check the shape of the run. The hose should follow the original path with no contact against cylinder or exhaust and no kink where it curves. Install fresh clamps over the fitting area rather than out on bare hose, and tighten only until the rubber is compressed — a screw clamp cranked down hard will eventually cut through.

Confirming It Is Sealed

Turn the petcock back on and give it time. Several minutes of sitting over clean cardboard will reveal a gravity leak that a quick glance would not. Inspect both connection points closely, by touch as well as by eye, since a slow weep often shows up as nothing more than dampness at the clamp.

Start it up next. Heat and vibration change the picture, so run the engine to temperature and inspect the joints again at idle. A leak appearing only when running usually means the hose is not seated deeply enough — take it apart and reseat rather than adding clamp tension, which only damages rubber.

Once it passes both tests, finish the housekeeping. Handle the drained fuel responsibly and think twice about reusing it if it has gone stale. Recheck the fittings after the first ride, since a new hose settles onto the barbs. Riders wanting a broader look at fuel line care and storage-related failures will find more in our broader walkthrough on dirt bike fuel line replacement.

Related Shopping Categories

Shop Fuel Lines for a 2018 Sherco 300 SE FACTORY Dirt Bike.

Shop Fuel Line Clamps for a 2018 Sherco 300 SE FACTORY Dirt Bike.

Shop Petcocks for a 2018 Sherco 300 SE FACTORY Dirt Bike.

Shop Fuel Filters for a 2018 Sherco 300 SE FACTORY Dirt Bike.

Shop Fuel Stabilizer for a 2018 Sherco 300 SE 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.