Running a Victor intake with a 1050 4500 and a 1 inch super sucker spacer on a 540. Vacuum signal at the carb is pretty weak at idle. Removing the spacer made a bit of an improvement but not enough. Maybe a 4 hole spacer might give the carb a better signal than no spacer? Any other ideas? Just trying to get the in gear idle a little better and not be overly rich to keep it running.

Vacuum or air speed signal ?

Holley Reg, Ultra or some aftermarket mod shop ? 2 or 3 circuit ? New ?

Have you found a sweet spot for initial timing ? This can really help. Hard to tune a carb if ignition is not correct.

More timing at idle

New Quick Fuel marine carb. 2 circuit, 4 corner idle. Idle mixture set on dyno and reset in the boat. Initial at 22°. Daytona box idle stabilization set for 850 rpm. Rpm in neutral 1100. Rpm in gear 600. 4-5 in. vacuum in gear. Tired of having it stall while trying not to hit things.

Degrees the idle stabilization is adding?
Cam specs?
Do you have a wide band AFR gauge?

Describe your idle mixture adjusting procedure in the boat.

Checked for leaks by spraying starting fluid. Idle stabilization is set to the max amount its capable of which is 20° Total timing 34°. Idle mixture initially set with vacuum gauge/ digital tach for highest readings and richened slightly after that when that proved unsatisfactory- but my vacuum port was in the spacer so now that its removed no more vacuum readings. Have a portable wideband but haven't utilized it yet. 663/241 646/246 on 112 cam.
Everything was done in stages. Tried with just carb tuning, then added idle stabilization then increased base timing.

Did you adjust the idle mixture in gear or in neutral?

Do you have full mixture screw authority (can you snub the engine by turning the mixture screws in)?

Engine is responsive to the mixture screws. Adjusted in neutral. Going to put some higher temp stats in to get some more heat. 140° is what's in it now.

Adjust the idle mixture using the same method.....but in gear