Sounds fine and doesnt sound like you have mechanical failure. Try a decarb treatment a couple of times. Could be that the rings are slightly sticking. Better sooner than later before the rings get stuck and start scoring...if they havent already. You could also fog the engine with fogging oil and let sit for a week and run the proper fuel mix with seafoam. Maybe that will loosen them up. Then refog for winter storage...or you could temporarily turn the idle mix screws 2-3 turns out to auto fog the engine...make sure you turn them back to original setting when you shut her off.
