I have a 2002 mercury 9.9hp motor. After a long night of fishing, I let my buddy drive the boat onto the trailer. I pulled it out of the water and drove home. The next morning I got up and saw that the gas line was still attached to the motor, which meant that he hadn't run all of the gas out of it. I also noticed that he had left it in "forward" when he killed it. I decided that I would go ahead and start it and run it a little bit with muffs and then unhook the gas line and run all of the gas out of it. Well I couldn't get it to start, and brought it into a merc mechanic who said that he could find nothing wrong with it but to be careful because it is easy to over-choke these motors. To make a long story short...ever since then I have had a lot of trouble getting it to start. I have to pull it at least 15-20 times before I can even get it to try and start, and when it does it sputters and dies. I changed the plugs and cleaned out the fuel filter and still no change. This motor never gave me problems before this and always started on the first or second pull. Should I add a cleanser in my gas like Barrymans B-12? I have no idea what to do now........any suggestions would be appreciated.