Question: What is the lean rich screw setting for johnson boat motor?

(Posted by: Tim on 2010-03-09 17:59:10)

I just bought a boat with a 40 hp johnson super sea horse what is the lean rich screw adjustment recomened setting?

Posted by: R S on 2010-03-09, 18:42:03

That is your adjustment for your gas to run it a little lean or you could run it to rich I would set about half way and try it if you run to rich it will foul out your plugs every time.

Posted by: Ӝ on 2010-03-10, 06:37:16

To set the low speed jet: Turn the screw all the way in (clockwise) until it lightly seats, then turn it out 1 1/ 2 - 1 3/ 4 turns. Start the engine and bring it up to operating temp. Turn the screw out until you begin to lose rpm. Then turn the screw slowly in, the rpm will increase. When the engine begins to lose rpm or falter, stop, and turn the screw back out 1/ 4 turn.