My speedometer isn't budging off 0 mph. I'm assuming my pitot tube (310DA - pitot only on stb outdrive...right?) is clogged. So I took the suggestion that I change my speedometer to use GPS (which is running fine with the C80), but the speedo is still at 0 mph. I did re-run the configuration to make the setting was saved. I plan on cleaning out the pitot tube, but any thoughts to why the speedo isn't working with the GPS? Thank you for the assistance.