I bought a pontoon a few weeks ago with the 90 hp 4 stroke efi motor. It had been stored for about a year and it had ethanol fuel in it. I drained all of the fuel out of it, cleaned the fuel supply module out, flushed the lines, cleaned the injectors, all are spraying good, installed new fuel filters and replaced the spark plugs. Drained the fuel tank and put good fuel in with seafoam, sloshed around let sit and drained again. refilled with good fuel, Non ethanol, and primed system and it started right up, ran good with water muffs on engine. when I put the boat in the water I ran it for about 10 minutes at high speed, idle down and get it up to speed 3 or 4 times, ran great.... then I can park it for about 5 to 10 minutes and start back up and take off and it sputter and will not speed up, will idle and then run rough til it cuts off, I can pull the cowl off and take loose the fuel filter going to the injectors and prime the system, have air and a little fuel at first then after 4 or 5 key prime it will flow solid fuel, snap fuel line back together and it will take off and run like hell until you park for 5 tp 10 minutes, fuel pressure while running stays around 44 psi at 4000 rpm, any help would be greatly appreciated,,,, engine has about 60 hours on it...
