Proper idle RPM?

[Cruisers Man]

Carb 5.0 engines. My port engine idles at 500 and my starboard engine idles at 800. What is the proper speed?

 

[kghost]

650 -750 in gear

 

[guyjg]

Idle speed is adjusted in the water and in gear as kghost said.

 

[Master mechanic]

Maybe one or both gauges is fugazied, look on the back of the gauge and cycle back and forth the switch a few times and then set the idle in gear on a warm engine the idle with a known good shop tach. The closest you can get to 600 that the engine idles well and shifts well without stalling.