1987 90hp Yamaha rich/lean question

[dfrants]

just got a 1987 90hp yammy on my Nitro today. she runs pretty good, but at idle seems alittle rough. the guy I got I from said he never liked the way it idled. I checked the plugs and they look fouled to me, like too rich. it ia oil injected so I'm thinking the carbs are set too rich. how many turns out from lightly seated do you start at on a Yamaha carb?

 

[robert graham]

On my 1999 C90 Yamaha I set those idle mixture screws at about 1-1/4 turns out from lightly seated....when I removed mine I sprayed carb cleaner into each jet port and the motor idles smoother now. My motor idles about 750 RPM fairly smooth, but not like a 4 stroke motor....just the nature of a highly tuned 2 stroke motor, I guess...I run that Pennzoil 100% Synthetic oil and the plugs don't get much carbon at all.....my little $15 Harbor Freight spark plug Sandblaster has been pure gold for all my spark plugs, outboards, mowers, blowers, etc.....all these 2 stroke motors love nice clean spark plugs!....