Bought w/ 12hr 4 weeks ago. used once(in salt), ran great. Flushed for 15 mins at home and ran fine then. Pulled out to start today and had probs. Pulled plugs showing flooding(gas) bad in #1. Finally got to start, ran rough would not idle. Checked compresion and 0 in #1 cyl. Any ideas, stuck valve is my guess? How to unstick without pulling the head?