The fuel line in a Troy-Bilt weed eater sucks gas from the tank and brings it into the carburetor. Each tank has a small hole for the fuel line to enter in an airtight manner so the pressure inside the tank and fuel systems remains high enough to continue in sucking gas. When installing new fuel lines into your weed eater, it's important to make sure the gas lines are airtight and properly secured to the tank and carburetor.
Drain all of the fuel in the fuel tank into a suitable container. Unscrew the rear air filter/muffler cover that sits on top of the air filter, carburetor and muffler. Remove the cover and lift out the foam filter pad from the box.
Unhook the main fuel hose from the carburetor with your fingers. The main fuel hose runs from the carburetor and connects to the fuel filter inside the tank. Reach into the tank and lift up the fuel filter with the metal hook. Unhook the filter from the fuel line.
Pull the old fuel line out of the tank if you haven't already. Cut the new fuel hose about 2 inches longer than the old one, usually about 5 to 7 inches in length, but more is better in case you make a mistake. Slice an angle into one of the ends so it makes a sharp point. This will help you push it through the tank easier.
Locate the main fuel hole next to the carburetor. Push the angled end of the fuel line into the hole until it extends inside the tank. Push the line through until just enough remains at the end to reconnect it to the carburetor. Snip off the angled end inside the tank. Push the new replacement filter's nozzle inside the fuel hose. Set them into the bottom of the tank.
Reconnect the main fuel hose to the intake valve on the carburetor with your fingers. Do not use a metal tool to avoid damaging the hose. Refit the air filter pad and the air filter cover onto the engine then refill the gas tank.