Hi!<br />I just bought a brand new 40HP Fourstroke EFI from Mercury. I ran it for the first time 2 weeks ago on the water for only half hour. I followed the break in instruction so I only pushed the throttle halfway up etc..<br /><br />Three days ago, I ran it again for almost 2 hours. But after 25 minutes, the engine started to act like if it was fuel starved. I had forgotten to open the vent on the gas tank. So I opened it.<br /><br />The thing is, after another 20 minutes it did the same thing, it did not stall but it revved down and up for a few times until I realeased the throttle completely. The outboard did this two times in the next hour until I got it back on the trailer.<br /><br />The folks from my boat shop examined the engine but they said everything was ok and that I should have turned off the engine, opened the vent, squeezed the primer bulb again and then restart the engine.<br /><br />I'm not sure I understand this. If the engine was running when I opened the vent, the fuel should still be pumped right?? Can someone explain me the principle of fuel primer bulb, fuel pump...<br /><br />I am a bit nervous about going back on the water again.