7.4 carb’d

I have a 93 Sea Ray 240 Overnighter with 7.4 Merc with Bravo One drive. I was trying to winterize the boat engine myself and had problems getting the antifreeze to go into the drive, and I may have ran the motor too long without water. The motor started to overheat, so I shut it down and let...

Had to replace my intake manifold due to a rusted hole in the exhaust crossover. I believe this is a common issue. Put it all back together and it fired right up. The issue is that the Rpm’s are surging at idle. 650-1400 then somewhere in between. Rev engine and it would have a very noticeable...