One thing for you to try first though is removing the melt filter if you still have it on - then see if output returns.  The screens won't always look clogged even when they are fully clogged.  Second - are you using a different material than you used to, or have you run a different material through that didn't work out and might still be in there?  If when you change material you just put new pellets in I've found that sometimes the old material actually keeps a lump inside the barrel that spins around as the new material pushes past it (different viscosity) so I like to heat it up, take the nozzle off, put new plastic in, turn the heater off, and run the motor just for a minute or two to have it push that lump out enough that I can grab it with a tool.  This only seems to happen when changing from something more solid to something that turns more soft (the soft material just doesn't have the strength to push out the other material - but just flows around it).

I am trying ti figure out why material is flowing rather slowly.
I upgraded to a 16RPM motor and extrusion speed is the same (very very slow)
I cant seem to figure out why it has gotten slow since i extruded last summer.