1998 Mercury Pro Max 300 HP bogging on acceleration after injectors flowed

[superboop]

1998 Pro Max 300 Mercury HP
Boat was running good maybe a little rich and a little smokey on start up but I ran 75.4 mph on GPS with my starflite. This was my first 3.0l pro max and one thing I noticed is it reved really slow off an idle. Compared to a 2.5l it had absolutely the slowest spin up in neutral if you tap the hot foot. If in gear it had pretty good takeoff
with a full load. With a 26p trophy plus I plugged all vent holes and used an exhaust ring. Then I had the injectors flowed over the winter. They were rich by anywhere from 6% to 10%. Compression test was even at 125 across the board. I replaced all plugs with champions, replaced the fuel filter and put back together.

After putting it together it is now super sluggish out of the hole and it
will bog so bad that when I have 3 people in the boat it struggled to get enough rpm to get on plane. Once it gets above 3k rpm then it takes off with full force and
blows the prop out. It’s like
something is stuck and then all of sudden it takes off and has all of its power and rpm. Fuel pressure is 37 psi. Do I have a bad tps or map sensor and it’s now
in some kind of limp mode? Any ideas on what I should test. I don’t have any guardian lights. I don’t have a ddt to scan for codes.

[David - WI]

Possibly the wrong spark plugs? (And not Champions!)... if that's all you changed?

[LakeFever]

Raise engine height or remove the prop ring see how it goes. Keep an eye on water pressure if you raise it

[skialot2]

Make sure you put all the linkage back together correctly. Do a complete link and sync.