I keep mine about 3/4 full.... the less air space you have in there the less condensation you will have but you don't want to fill it all the way as the gas will expand when it gets warmer out in the spring. I found that out the first year I had my CC.... I filled it up all the way and in the spring when I cut the shrink wrap off it was like a bomb in there. My fuel tank vent was thru the fill cap which was inside the shrink wrap......(I added a vent for the fuel tank to the hull to make sure that never happened again) if I had know what I know now I would have thrown a match in there when I had the chance
