I have been having some problems with my 70hp Yamaha. Last week it had a gradual loss of power and then just quit. It idles fine until I give it some thrust and then it quits. I replaced the spark plugs last week which seemed to help until I put the boat into reverse to exit the dock and gave a little thrust and then it sputtered and quit. Once it quits it will not start again. I had roughly the same problem a year ago and the mechanics replaced the diaphram, fuel pump and pumped water out of the gas. I am not mechanically inclined but this happened right after I re-fueled so I am wondering if I got bad gas or it is something more serious.
