I have a 85' Merc Black Max 175hp, yesterday at the lake it sounded and felt a little different in idle (kinda like a hose was clogged and no gas was getting to engine) it took it a little longer to get on plane but once it was on plane it cleared up....kinda sounds like the carbs are clogged or maybe spark plugs but I'm no mechanic so if yall have any suggestions or input it would be greatly appreaciated!

I would look at the inside of the fuel line to make sure it isnt coming apart on you.

How old is the fuel?

Check spark and compression