HELP 2018 FI23 with 6.0l 409hp Crusader Performance issues

[Zinger16 0]

I have a 2018 FI23 with the 6.0l 409 hp motor at sea level in portland oregon.  The boat has 149 hours on it and i just re changed the engine oil and fuel filters. The boat has a 16x13.9 prop.  I u

 

The problem --     The motor runs good then it will run like it lost 70 hp....  unloaded you can feel it not pull as hard and take longer to plane.  Then later in the day it will jump out of the whole no problem.   Last night we went to surf and when we started we couldn't get tot surf speed until we dumped about half of all the ballast.  An hour later i refilled the ballast and it pulled it the rest of the night no problem.  This happens all the  time.   A few nights before it ran great as soon as we got into the water. After about 45 minutes of surfing it wouldn't get to speed and we had to dump 30 percent of the ballast for it to make speed again.  A couple hours later it started running great again and filled everything back up and pulled with ease.....

IT doesnt miss... and make any unusual sounds when running...  running 92 octane ..   No codes are thrown and its running at 167 degrees 

 

Any thoughts here ??? Please Help :-) 

Edited September 3, 2020 by Zinger16