mike,

There are 3 filters, well the one in the tank is actually more of a strainer. The intermittant problem suggests to me that is the fuel strainer in the tank.

Take off the rubber fuel line where it connects to the steel line and observe how much fuel runs out. Steady full flow stream, the strainer is OK. Slow flow or dripping, the strainer is plugged.

If strainer isn't plugged, take off the in-line filter. Try to blow thru it in the forward direction. If fuel squirts out easily, filter is OK. If hard to blow thru, replace the in-line filter.

If the in-line flter is OK, replace the canister filter. Only test of this is how the engine runs.

Your problem could also be an air leak in the fuel system. Check for any leaks in the fuel line or the primer pump.

P E H