yamaha 150 fuel/air adjustment help

[Backchannelmako]

I did a google search and could not find my answer and i do not have a service manual yet. Looking for help adjusting my fuel/air mixture adjustments on my carburators. My motor is a 98 carbed 150 yamaha. The issue i am having is that the motor will stall at idle. when i put it in gear and run above 1000 rpm it runs beautifully. when i am at *****ing speeds around 700 rpm it will also die ocasionally. Before i tear the carbs apart i wanted to check the fuel/air adjustments. when i adjust these is there a specific amount of turns out they should be, like tighten them all in and turn out 2 1/2 turns?

[rodbolt17]

air/fuel ratio is fixed on that carb.
the screws simply allow more or less of this fixed ratio into the intake.

screw setting will depend on what MODEL 150 we are discussing.

[Backchannelmako]

i believe it is the S150. carbed 2 stroke 6 cyl saltwater series 2

[rodbolt17]

S150 sets at 1 1/4 turn out from lightly seated.

[Backchannelmako]

Thank you. does that seem like the right thing to do and do you think this may solve my problem? or probably just carbs?

[99yam40]

screws do not normally move by themselves,
may need to pull and clean carbs up and readjust everything when put back on

[rodbolt17]

like I said.
those screws DO NOT alter the air to fuel ratio.
the A/F ratio is FIXED by the pilot air and pilot fuel JETS.
all the screws do on those carbs is allow more or less of this FIXED ratio into the intake.
clean the carbs.