My Merc is new to me (2 months) a 2001 Mercury 50 hp 4-stroke, non-efi (has carburetors), 4 cyl serial 0T229967, SMALL Foot gear ratip is 1.83:1 (so Not a big foot) , , had been mostly fine, except recently at idle and very low speed, alarm horn under dash started coming on once on while so...