I have a 1999 signature 300 with twin 5.7 Volvo pentas in it. I have been having in issue and no idea what caused it. If I am at the dock and in neutral the engines purr like kittens and will rev up to 5k rpms no issue. Once I exit the marina and accelerate they bog out at about 2K rpms I can't even get it up to cruising speed. I return to marina and have fouled plugs, not all just 4 or 5 of the 16. I have had three mechanics work on it and none can figure out the issue. Fuel filters have been changed, carbs rebuilt, timing set over and over again, new plugs 5 times so far, distributor cap and rotors are fine. Still no idea what the heck is going on that limits the power when underway. Its like there is a governor on it, which there is not . I NEED HELP ...
