New strainer baskets now no water flow?

[READY]

This is for the new to me 1976 48LRC. Impellers were changed 3 months ago and it has been running fine with good flow. Before the trip I pulled and cleaned the strainers. Reinstalled and all water flow was good.Made a 10 hour transit. Then changed to new strainer baskets as previous ones were not in good shape when I checked them prior to the trip. Now on engine start and after several minutes at fast idle no water coming out of exhaust on either engine. I have checked the following:
Seacocks open
Crack open top is strainer (eng. Off) and water pours out as expected
Removed strainer basket entirely still no water
Tried to troubleshoot on port engine as access is easier. Check impeller and it is good, had some water in them and not dry.
Removed water intake hose at seawater pump and only for a little water came out.
Tried to prime by the filling that same hose and reattaching to seawater pump.
I am checking now to see if I get good flow in this hose that runs from strainer to seawater pump by disconnecting both ends and flushing freshwater from a garden hose
Still no water flow. I presume there is some vacuum lock or something I am missing but as I pulled these for cleaning before and reinstalled prior to trip and did not have a problem I cannot figure it out.

 

[STB]

Just as a saniry check....what happens with no baskets at all?

 

[READY]

Sorry but I was able to resolve. Cannot explain why the problem did not occur when baskets were checked 2x before. But I removed the strainer out put hose, filled strainer to full from freshwater hose and then filled hose from strainer to seawater pump. Flow is restored!

 

[O C Diver]

Probably air bound. If it happens again, try revving the engine up for a few seconds. This often is enough to get water flowing.

Ted

 

[C lectric]

I am going to guess you had an air leak from a questionable seal or gasket. When it finally worked you got it resealed properly.
Does your unit use flat gaskets. Are they cork? Carry spares?
. If so then they are prone to leaks and weeping also. I don't know whose strainers you have but rubber/nitrile ones should be available and are far better.
There may have been just enough air sucked in to prevent the pump from pulling/priming. With a proper seal the pump was then able to prime.

 

[Comodave]

Don’t you hate it when you do a simple job and it turns into a can of worms. Glad you got it fixed.

 

[READY]

Thanks for all the advice. I did make new gaskets from cork. I feel like rubber/synthetic would be better but what is the consensus? Also I did try revving the motor briefly but did not want to stress virtually new impellers. As best as I can figure there was air either in the basket or in the hose that created the issue. This is my second Hatteras but very different setup so it will just take time to learn all the quirks. Actually this problem has got me thinking about installing a freshwater flush or winterizing feature. It seems most of that is in place already so it won't take much effort. Here in SoCal we don't winterize but hope to have her in the PNW someday.

 

[C lectric]

Groco and Perko used to use only cork. Now they offer nitrile.
I quit using cork years ago [~30} as it was not long after new gaskets that it started weeping/leaking.

I got fed up and modified the glass and the cap to accept O rings. NO more leaks

 

[READY]

That was the test just to confirm the problem had nothing to do with the baskets. When removed still no flow. All good once I removed all possible air pockets.

 

[Pete Meisinger]

Two ideas, now that they are not needed.

"Blipping" the throttle several times often starts a sluggish flow. (Sort of like when you were a kid sitting at the starting line with your jalopy with the pipes open)

Next time you replace your impellers be pretty liberal with the KY jelly or dish soap. That will help the impellers get some suction going.

pete

 

[HopCar]

Like Clectric I suspect an air leak.
As to the subject of cork or rubber gaskets, older Perko strainers used cork and newer ones use rubber. Perko says you shouldn’t interchange them and the last time I checked they still had both in their catalog.