I have a 2000 Yamaha 2 cylinder 15hp 2 stroke outboard that wont run unless the choke's on at least half way, whether at idle or at full throttle. The motor has sat for about 2 years but is in good condition. I have had the carb off and diassassembled it and it looks OK. Fuel appears to be flowing to the carb OK. I have also changed the fuel. <br /><br />I would appreciate any suggestions. Its driving me nuts.