Re: Adjusting the carb on a 1953 Evinrude 15hp
The top needle is for the low speed. Slowly turn it clockwise until it "seats" or bottoms out, being careful not to damage the tip of the needle tightening it too much. Once seated, back it out 1.5 turns. Do the same with the bottom needle, or High Speed, but only back that one out 3/4 of a turn.
Now it is best to fine tune it on the lake, where there is proper backpressure on the exhaust.
Slowly turn the low speed needle in, clockwise, 1/8 of a turn or so at a time, giving it time to respond. Once it starts backfiring or wanting to die, turn it back out 1/4 turn. Within that last 1/4 turn is the ideal idle position.
Then take it for a high speed run, doing the same with the high speed needle, turning it in 1/8 of a turn or so at a time until it backfires or wants to die, then back it out 1/4 turn as well. Within that 1/4 turn is the ideal position.
Now reset the dials so that they are pointing straight up and down, vertical. This is for reference so that you know where they should be if they get moved.
