1990 50ESD-JD Top End Problems

[MTOutboardJets]

Hello all,
I have a 1990 50HP and have lost 5 MPH up and down river, originally thought this was due to a corroded exhaust manifold but replaced with a new performance tuner as well as put performance reeds in... this all had little to no effect on speed or HP. Have now began to focus on the fuel system as my spark plugs were black and oily/wet, I put the boat in the water, adjusted the linkage so all my carbs were in sync then proceeded to adjust my pilot screws to specs (1 7/8) and tightened them from there to get a good idle, got it running good from what I thought and ran it for a bit and looked at plugs. they had black carbon buildup on top threads indicating still rich with pilot screws at around 1 1/4... Right? Any info or advice would be appreciated. The best I could get it to run was still not great, I have some rattling/knocking that I also would appreciate any thoughts on? Ill include some videos, the noise is happens during lower RPMs and Idle.https://www.dropbox.com/t/JonKNNsIeFQRm2ee
Thank y'all!

[ausnoelm]

Might be a small air leak, a slightly blocked carb, a damaged prop, timing slightly off, throttle not fully opening, choke slightly on, a bad spark plug, water in boat, adjusting the mixture screws do nothing for high RPM running.

[99yam40]

make sure the rubber plugs are in the holes where the pilot jets reside.
if they come out that allows fuel to flow thru both main jet and idle jet from the fuel bowl causing rich condition at high speed.
all of the fuel should go thru the main jet before hitting the pilot/idle jet.

Also have you checked the fuel pump to see if it is leaking into the #3 crankcase?
but that would not affect all 3 cylinders

I fought something similar of my C40, finally figured out someone had drilled out the main jets.
installed new ones and the high speed miss went away

I am not sure I understand these carbs. looks like it might have an early kind of prime start system, but I do not see a red lever to turn from auto to open, to off.
and #41 is called a solenoid valve