Just bought a 2018 Bennington 21slx on Friday. Currently am breaking in the 115 hp mercury. After the first two hrs of the break in the engine is running perfect. I am cruising between 4200-4500 rpm and increase throttle to wot. The motor starts to miss and drop Rpm's. I back off all the way to idle and then back up to half throttle and the engine runs perfect. This happened about 10 minutes later it happens again. There were no engine warning signals from the engine management system as the manual states will happen if something major internally happensSo I pull over and start to troubleshoot. Everything seems to check out fine. I open the gas cap just as a curiosity and air starts to rush in. Sounded a lot like when carbureted engine fuel tanks would become vapor locked. After that boat runs perfect holds speed and Rpm's without an issue. Runs perfect all the way even at wot. Is it possible to have gotten air in the fuel line or maybe something else is going on? I know fuel injected lines typically do not become vapor locked. Any help or suggestions appreciatted. This is my first fuel injected outboard so still new to this.
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