high/low valve adjustment

[cschmid44]

Ive got a 1971 evinrude model number 40152B. I was wondering how to adjust the high/low valves so there correct? Also out of curiosity what the purpose of the valves are? Im new to all this boat stuff and trying to learn. Thanks for the help.

[boats.net]

The upper controls the low speed air/fuel mixture (idle), the lower controls high speed air/fuel (WOT). You should start around 1-1.5 turns out (on both) and adjust from there.

[cschmid44]

Thanks. Can the adjustment make the boat go faster?

[boats.net]

Depends on how it was running top end before. You cannot gain excessive power with the adjustment.