I guess I should give details. This is my fourth year with the boat . I have twin F225. In the first month of owning the boat the issue arose. So I brought to one of those Yamaha certified mechanic after loosening my wallet of 1k he replaced the pressure relief valve. Boat ran great the rest of the season. On to year two always the same time june the issue comes back again. This time I have a look and see what is an obviously a used pressure relief valve. I replaced it and off we went for the rest of the year. On to year three here we go again. Thinking no way again not again here we go . This time I was suspecting it was the lift pump. Nope I replaced it and still happened. So I replaced the pressure relief valve and off we went. And on to year four and here comes just about june and here we go again. Now keep in mind I have two motors and only ONE problem. I removed the vst and replaced the float pin and checked and cleaned the vst ,spotless. So of course this didn't work . I was reading a really good thread on the issue of vapor lock and fuel issues. The issue only happens when hot. I can run the boat all day and never shut it off no problems. Its only when I restart after sitting a while 30-60 minutes. Opon acceleration the motor just dies. I can squeeze the primer ball 4 to 5 times .starts right up and off I go.. So I read about direct venting the vst .,removing the vent orifice so I tried that . That seemed to do the trick until the engine died again. So does the fuel have something to do with it, because it sat all winter. I have pressure checked the system with compressed air. When I removed the vst vent orifice it didn't pass and air so that's what made me think of overpressure in the system. So how's that for a brain buster...
