How is water flow controlled with Captains Call

I have a Merc 5.0mpi with the Captains call option. I have noticed that the flows out the thru hull ports with the ACC switch off (the thru prop position for the actuators) and with the ACC on (the thru hull actuator position. How does the actuator control the ehaust and water?? I can definately see (bubbles in the water) and hear the exhaust the fact that water is ejected from the thru hul ports (at least when idling at the dock when I can get back there and observe) seems strange to me.

I ask this becasue, when the engine is in the warm up phase, I get water from both sides of the thru hull ports in both the thru prop and the thru hull position but once fully warm it seems i get water from both sides in the thru prop position and only flow from the starboard thru hull port in the thru hull position. I have chaeked the mainfold temps (just by touch and not measured) and they seem to be very close in any actuator position. Any thoughts??

Re: How is water flow controlled with Captains Call

Captain's Call uses a solenoid-operated big butterfly valve in the exhaust to control the flow. The butterfly valve is not a perfect fit so you'll always have some leakage around it. It'll leak a little into the thru-hulls when it's in the closed (thru-prop) position, and a little into the prop when it's in the open (thru-hull) position.

Re: How is water flow controlled with Captains Call

That is whow I thought it worked, a simple flap driven by the actuator, however, then it doesn't seem to make sense why the water flows in the thru porp position and not in the thru hull.

Re: How is water flow controlled with Captains Call

Take it apart & look at it! You'll see then.

Re: How is water flow controlled with Captains Call

You should be able to see the linkage connected to the big solenoid on each side that controls the flow. Make sure you're getting a big click out of both solenoids and both linkages are moving when you cycle the switch.

The switch position won't make any difference to manifold temps, the valves are downstream of the manifolds.

Re: How is water flow controlled with Captains Call

That diverter plate is not water tight by any stretch of the imagination. Wasn't designed to be.