lose of Rpm's over 3000

[Gtalotta]

i have a 97 Maxum 3000 scr with twin mercs 4.3, my starboard engine doesn't go over 3100 rpm's. i had the hull cleaned, motors have 360 hrs on them, trim and bow adjusters working fine. fuel filters replaced. i also have ran seafoam through the systems on both engines. but the boat won't go over 13 knots. does anybody know anything about this issue?

[mmwjr]

Did it loose a cylinder, perform a compression test. Are all cylinders firing, check to see what the spark plugs look like. Check fuel pressure, may be starving for fuel.