My 90's Mariner 135 V6 is running rough. Put in 6 new plugs and run some Redex through the petrol. Tickover not too bad but pick-up and top end not quite there. Max revs appear to be @4500 rpm under load but revs easily to 5500 using just the fast idle lever.......
Starting a bit hit & miss sometimes needing choke but not guaranteed..
Any clues where to look next. I'm not keen to strip the carbs down as the river is tidal and I'll probably lose something.