This winter I replaced some of my bottom fabric and static ports. My airspeed was slightly lower after this small project. Thinking I had blockage, I disconnected my static lines and blew them out with air. But, no change. Checking my AS indicator, I flew the plane steady in 4 directions, 90 degrees apart and a averaged my GPS GS and indicated AS and found my indicated AS 8 mph low. Then I disconnected my static line in the cabin and my indicated AS jumped up 8 mph. I rechecked my indicated AS and GPS GS with the static line disconnected and my average GPS GS and indicated AS matched.
Any ideas?