Re: need help on adjusting the carbs on my mid 70s 150hp inline 6cyl merc
After a good cleaning/rebuild a good starting point is with the Idle set screws 1 1/2 turns out from being lightly seated.With the boat in the water and warmed up put her in gear and start from the top carb down.Slowly close the Idle set screw until the motor starts to die and bring the set screw back out 1/2 turn.Repeat this on all 3 carbs.Take your time to give the motor to adjust to the settings.After that I would give her an extra 1/8 of a turn out on all 3 carbs to make sure she is not running to lean.Next adjust your Idle set screw to the best Idle without dying 700 RPM would be good in gear.Give her a good hole shot and see how she performs,
if she falls on her face back out Idle set screws another 1/8 of a turn,repeat hole shot.
This takes a little time getting this down.Good luck I am sure some of the other guy's on here can maybe explain this a little better than I can.
