Livewell thruhull turns but doesn't open

[Beyond A Wake]

I assume the Livewell on my boat has never been used. Tried it out and pump ran when seacock open but no water showing up.
Put boat in wash rack and set up hose to clamshell under boat and opened seacock, ran pump, NO water. Opened plastic "NUT" on pump lower side tried again with water and seacock open and no water Showing up.

Seacock turns with handle and rotates shaft. So question is whether the ball would be stuck but shaft still turns and what function does small "screw" on side of valve serve. Didn't take pictures but all my valves are similar so assume it is a standard GW uses.

Did not peek into clamshell but all other ones look the same and no growth on them on surface anyway. Boat has been first lift kept and now in dry stack rack.

If there were to be growth etc in clamshell could it really clog it entirely so no water would seep through?

Boat show day tomorrow in FL Ft Lauderdale so will also ask around. Together with my Radar problem Raymarine, only showing targets up to 2NM.

H

 

[Hookup1]

Seacocks that don’t get operated regularly barnacle up and break off the shaft. Pull the hose and look down inside to see if it moves. That cap is a drain witting for winterization.

May be able to rebuild but replacement is easier.

 

[seasick]

It may be easier to pull off the hose in the bilge and run water into the fitting/seacock. You will know for certain if the flow is normal,slow, or blocked. In addition, if there is gunk, the reverse water flow may help clear it out. Have you verified that when you turn the handle, the shaft is turning (look at the threaded shaft where it sticks out past the handle nut. The handle lever may be slipping.

 

[seasick]

Forgot to mention; the pump could be bad ( impeller shot)
I also forgot to ask; Is there a dual output pump connected directly to the seacock fitting? If so the aux output fitting on the pump is usually for raw water washdown. If you have such a installation, it would help to do your test for the raw water setup

 

[Legend]

ncI one had n eel in my live well hoae blocking the water - you will have to go through the process of elimination to find out for sure

 

[Beyond A Wake]

Update;
went to boat show and spoke to Grady folks.
So I opened the livewell pump top, pulled it out and could look down the valve and see it operating properly and pouring some water in it drained out of pump. So not a valve or lack of water issue.
then I looked at impeller and ran pump, impeller was not turning but motor ran.
So I realized the construction is ingenious, a magnetic transfer of power from motor to impeller and since impeller was stuck the motor just ran without moving impeller.
freed impeller up with some rust removing/preventing lubricant CRC 55?. After a soak and turning it freed up and I finally could get it out of the housing and clean it all up and getting running as should.
So learning was that if motor runs, open it up from top and pullout the assembly after which one can pull off the impeller part and clean things up and pump is restored to former glory.

H