First time boat owner. I just purchased a 99 Regal with a Volvo penta 3.0. First day I had it out on the water it won?t accelerate past maybe 5-10MPH. Idles at around 2k rpms and full throttle around 3K rpms. Engine noticeably stops applying power about 1/3rd throttle and boggs down a bit. I can ease off of the throttle and bring the engine pitch back to normal, but boat will not accelerate or plane. Boat has had some recent work on the prop such as throttle cable, shift cable, exhaust bellow, drive shaft bellow, and trim sensor. After getting one of my buddies to look at it we replaced distributor cap, plugs and wires and rebuilt carburetor in an effort to get it to run with no luck. Any ideas?