Re: WOT on 4.3 merc
I did some checking with various sisterships offered for sale. My guess is that yours are the 190 horse engines, and I am pretty dang confident you are close to max speed. There are many of these out there with the Volvo 220s and they are not reaching high 40s. If the tachs are right, then props are not. If the tachs are wrong then the props may have too much pitch, but I do not think you have a confirmed performance problem at this point. I do think you have the 1.81 ratio and that tells me the tachs are off too . . . How were they "checked"?
I cannot explain the high readings stored on the GPS unless it was on the trailer, but one thing you can take to the bank: personal boats, with stuff on board NEVER reach original test speeds. They just don't, and you can find 1000s of examples. My boat "tested" at 62, and I have maxed at 57, I have played with props and weight balance and thrown everything out except the key and still nothing higher. It's just the way it is.
Why do I harp on this? Because you will spend thousands chasing a phantom if it is indeed a phantom. Right now I am leaning towards phantom problem. Fuel pumps, timing, ignition issues, vents etc. all need to be confirmed with proper diagnostics, not with guesses. Altitude? hadn't thought of that until this minute. Do you have fuel flow info? If they're flowing the rated fuel, then they are most likely making the rated power. Stuff like that is really important to this discussion . . . Good luck. We will help with whatever we can.
Ok let me slow down a bit...I have a 19' boat 220hp 4.3 does 56 at 4900 with a 21p prop...Its 3400lbs with me and the gas..few beers. Now if i add 6' feet of length and 7000lbs of people...thats 30 plus people....Is that boat going to slow down a bit...
