Figuring out problems with scooter fuel line flow can be a bit irritating if you don't have an idea of how to go about it. However, the problem is not hard to solve. The issues with fuel flow tend to be limited, so you can use a process of elimination to sort the issue out quickly.
Look for leaks. Review and examine all the joints and connection points for your fuel lines. If the fuel line looks old, cracked, or worn, get ready to replace it. Check your banjo clamps on the fuel lines to make sure they work and are not rusted out. Work along the fuel line looking for pinches, cracks, holes, or tears. Disconnect the fuel line from the scooter carburettor and let the fuel flow into the hose while plugging up the free end with your finger. If there's a leak, be prepared to see it.
A pinched line can also stop fuel flow. Look at your fuel line from the tank to the carburettor. Make sure the line is not getting bent wrong or pinched between mechanical parts, which would cut down fuel flow.
Check the inside of your gas tank to see if it's clean. Sediment can pile up at the bottom due to rust or gird; use a flashlight to see if the bottom is clean. If you have to, be prepared to remove the fuel tank and check the fuel filter and spigot coming out of the tank. You may need to drain the gas from your tank to do this.
Using screwdrivers to release and later tighten the hose clamps, remove your old fuel line rubber hosing and replace it. Most scooters use 1/4-inch hose, which you can buy at most auto part stores. By using new fuel line, you get rid of the guesswork in wondering if your fuel line is split or cracked somewhere in the system.
If your scooter tank is dirty or rusty, remove it and drain it. Put the gasoline in a gas container. Remove the tank spigot and fuel filter if included. When drained, have the tank blasted by a professional cleaner. When cleaned, reinstall the spigot and a fuel filter, if needed, and reattach the fuel line. Then reinstall the tank in the scooter and connect the line. Use new gasoline when filling up. Get rid of the old gasoline at a petrol station or hazardous waste site.
If the problem is in the carburettor, remove the lines and remove the carburettor. Disassemble the unit and clean out all parts with carburettor spray cleaner. Dry with a rag and then reassemble. Reinstall the carburettor with new gaskets and reattach the fuel lines.
Completely changing out your fuel line with new filters, banjo clamps, and fuel line can solve a lot of age-related problems. Gasoline eats away at rubber and filters, so it's beneficial to replace these scooter parts after two or three years.
Gasoline is extremely flammable. Make sure that you have any heat or flame sources kept far away from your fuel source. It helps significantly to work in a well-ventilated area such as an open garage with a fan going. Do not smoke, start an engine, or use any electrical sparking equipment near the fuel. Gas fumes travel along the ground and can ignite, even if not seen. Make sure to throw away all used shop rags in an outside garbage can after finishing the job. Don't pile them up in the garage, especially not near a house water heater.