The rubber gasket on bottom of gas tank where fuel line exits is torn and leaking. The valve is fine.

Check the gas cap and the carbon canister. There is a pressure sensor on the fuel tank that has a gasket that can leak. Cracked fuel return lines can leak too. Look under the hood for wet spots that would indicate a leaking rubber hose on and around the fuel injectors.

There could be a bad check valve in the carb or a gasket leaking or even a pin hole in the fuel line. Since its the primer bulbs job to remove air from the carb and replace it with fuel; as long as the unit runs fine I wouldn't worry about it. A leaking gasket can be fixed with a rebuild kit. Bad check valve will require replacing the carb.

Make sure the lines coming from the gas tank are sealed at the point where they exit the tank (the rubber grommet where they run through) and make sure there are no cracks in the fuel lines you also should check the passages in the carburetor and the diaphragm to ensure they are clean.

its possible that the fuel lined have some type of misalignment issues where they are connecting, causing the gaskets to have side loads they were not intended for. The vibrations from driving are probably exaggerating the misalignment and prematurely wearing things

EVAP System Vent Circuit Malfunction

This diagnosis detects leaks in the Evaporative Emission (EVAP) purge line using of vapor pressure in the fuel tank. The EVAP canister vent control valve is closed to shut the EVAP purge line. The vacuum cut valve bypass valve will then be opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP control system pressure sensor can now monitor the pressure inside the fuel tank. If pressure increases, the Engine Control Module (ECM) will check for leaks in the line between the vacuum cut valve and EVAP canister purge volume control solenoid valve.

Possible causes
- Incorrect fuel tank vacuum relief valve
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- Leak is in line between intake manifold and EVAP canister purge volume control solenoid valve
- Foreign matter caught in EVAP canister vent control valve
- EVAP canister or fuel tank leaks
- EVAP purge line (pipe and rubber tube) leaks
- EVAP purge line rubber tube bent
- Blocked or bent rubber tube to EVAP control system pressure sensor
- Loose or disconnected rubber tube
- EVAP canister vent control valve and the circuit
- O-ring of EVAP canister vent control valve is missing or damaged
- EVAP canister is saturated with water
- EVAP control system pressure sensor
- Absolute pressure sensor

Possible solution
- Loose fuel filler cap
- Leaking fuel filler cap


Hope helps (remember to rate this answer).

The leak at the fuel tank is not related. Sorry. What you have is a blockage in the carb itself. Take it back off, take it apart and carefully clean all the orifices. In the plate under the primer bulb, there is a one way valve. Make sure it is clean, use aerosol carb cleaner and spray thru the valve. Remove the locks from the adjustment screws and remove the jets one at a time and blow carb spray thru them also. If you did not replace the strainer screen before, replace it now. It is located under the plate nearest to the fuel inlet. When reassemble, make sure the gaskets are in the same order as the originals. Diaphragm side...paper gasket against the carb body, then diaphragm. On the inlet side, thin cellophane first, then the thicker gasket, then the outer plate. The adjustment screws should be turned out 1.5 to 2.0 turns.
Good luck!

If air leaks when motor is off, fault most likely in-tank check valve. Follow discharge air line from pump to tank. Brass/steel valve at tank is the check valve. Remove hose to valve and check for leak. Replace as needed. If air is leaking while motor is running fault could be reed valves in head. Faulty reed valves in head, or torn head gaskets will cause very hot discharge air and tank will most likely never fill to shut off (or take a very long time to fill)

Be sure to not overfill the tank. Just load it with gas up to the bottom of the neck and be positive you're not cross-threading the cap when twisting it on. If it only leaks when operating, see if there is fuel bubbling out through the vent(s) in the top of the cap or out from under it. Also wipe the tank clean and dry to be positive it is not leaking from a seam or crack in tank or around fuel lines. If leaking from cap, might have to replace as they do have an internal rubber seal that could have gotten dry or cracked. If it's from the tank seams or fuel lines replacement may be neccessary of either one or both.

Check and see if you have any gas on the ground after you park your car. Check around the gas tank and gas cap. It's possible that the fuel pump (which is in the gas tank) has hoses that may be leaking. If this is a slight leak, it might only manifest itself via a gas odor into the trunk or passenger compartment. It might be a good idea to put the car on a hoist and follow the fuel lines from the engine to the fuel tank. There should a one line that takes the fuel from the fuel tank to the engine and another that brings back the excess. There should also be another line coming out of the fuel tank that is for venting. Unfortunately, the fuel pump and hose connections are not easily accessible and require either removing the gas tank or cutting a hole in the trunk to access it. You should definitely take care of this soon as leaks don't get better, only worse and it is a potential fire hazard. Good luck!

i had the same problem with my trimmer. you could replace the fuel line but if you don't want to hassle with fishing it thru the hole i suggest going to homelite.com and ordering the gas tank. it only cost me $18 with shipping and came with everything (tank, lines-with fuel filter, and gas cap). all you need to do is take out the 4 bolts on back of trimmer and the 2 top bolts holding the housing together. be careful not to nick any gaskets especially the one behind the 4 bolts. this is the crankcase gasket. also don't get anything in the crankcase that will score it as this will ruin the trimmer. also there are 3 spacer gaskets that go in the holes in the fuel tank and i believe a plastic heat shield between the gas tank and the bottom of the trimmer. you will see this when you take the tank off. just be careful and be sure all the bolts get tightend up (especially the 4 on the back as this is the back side of the crankcase). it only took me 15 min to replace it and the trimmer runs great. all the above info is if you have a trimmer with the gas tank on bottom. if the tank and gas cap are on top hopefully someone else will be able to help.

good luck