Idle speed is set by the PCM and is not adjustable. A faulty idle indicates a more complex problem that should be diagnosed.
Idle speed is set by the PCM and IS NOT ADJUSTABLE.
Top of the throttle body.
vacuumm leak
On the top of the manafold.Itd literally under the windshield.
It will not idle at the proper speed (750 RPM).
No, it wouldn't affect the idle unless you were somehow overheating the engine.
Idle speed is set by the PCM and is not adjustable. The screw you are fiddling with is just the stop screw to adjust the initial throttle plate position, it should not be used to attempt to adjust the idle.
The IAC valve is located on the top/rear of the air intake plenum beside the throttle cable. You will need to look under the cowl to see it.
1978 80 Mercury Outboard IDLE ADJUSTMENT
You adjust idle with idle timing
The idle is not adjustible. You may need to clean the throttle plate to improve the idle.
There is none. It is electronic. Try replacing the idle motor.