Rcurren01 rcurren echo srm 225 trimmer you can try with fuel cap off in case the caps vent is plugged not allowing fuel flow and or replace the filer in the tank if you have not already done so still no go if you say primer bulb shows fuel in it and you press the primer bulb say 10x and choke on and still no fuel in engine the carburetor is either not adjusted to allow fuel to enter.
Weed eater gas tank pressure.
In my case it does not it will actually drain the tank withing a few days through the carb.
I believe that the tank builds up pressure during running and i think that the fuel cap should relieve it back to atmosphere after it has been shut off.
This cycle needs to remain completely airtight otherwise fuel will start leaking from either the broken seal or from another area in the fuel system.
The fuel in your weed eater must flow uninterrupted from the tank to the carburetor from the carburetor to the cylinder and all excess fuel must return to the tank.
The plastic gas tank in a stihl weed eater as with other weed eater gas tanks holds the machine s fuel supply.
If a stihl trimmer gas tank is compromised in some way the machine won t work at full capacity.
Gasping for air priming begins with air pressure caused by pushing air out of the primer bulb into the fuel tank.
Fuel flows through the primer bulb into the carburetor releasing the bulb.
Plus if the stihl trimmer is leaking gas it can pose a significant safety risk.