Perko 493/500 water strainer blocking flow to water pump?

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richsailorman
Posts: 7
Joined: Mon Oct 04, 2021 6:16 pm

Perko 493/500 water strainer blocking flow to water pump?

Post by richsailorman »

Freedom 32 with Yanmar 3GM30 engine
Our engine has been working great, yesterday we ran it for an hour after putting in a new alternator.
Today we were going to motor off the mooring and the engine started right up, however there was no water coming out of the exhaust pipe.
We shut down quickly and started investigating.
My first thought was it was the impeller in the water pump.
disconnected the hose at the inlet to the water pump and found no water getting to water pump.
Then I took off intake hose at the raw water seacock, good flow through the seacock.
Followed the hose up to the water strainer.
Disconnected hose from water strainer and poured water through end of raw water hose at input to water strainer and hose appears to be clear.
Lifted top of water strainer screen a few inches above housing and put it back.
Reconnected hose to sea cock, and then inlet to water strainer still no water arrives at input to water pump.
The water strainer looks relatively clean, although the screen looks like it might not be vertical. Could this be blocking flow?
I couldn't disconnect hose at output of water strainer since it would not come off, I'd have to cut it and didn't have a replacement handy.
Am I missing something obvious... must water pump connected to impeller needed to start flow?
Next step removing water strainer from boat and giving it a thorough cleaning and inspection?
Thanks for any help.

BillSmith
Posts: 92
Joined: Tue May 24, 2016 7:56 am
Location: San Mateo, CA

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by BillSmith »

Doubt this is your problem if strainer was not recently installed but reminded me of a story.

Broke the drain plug on strainer. Foolishly decided to install a new strainer. Should have just epoxied the plug. Had hired a 'mechanic' to do other work, included this simple task to give him so more hours and make trip to boat worthwhile.

I watched to learn and noticed he mounted the new housing backward to flow. When fully installed, guess what, the water didn't move. He questioned the impeller. I commented perhaps it was the inflow/outflow was the issue. Oops!

He sheepishly remounted and strainer did its intended job then and since. Never could get him to come back and do anymore work. Ha!
Bill & Carole Smith
Freedom 35 Pedrick
SweeTART
Coyote Point
San Mateo, CA

AlanK
Posts: 127
Joined: Wed Dec 10, 2008 6:59 pm
Location: Freedom 33 Boston, MA USA

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by AlanK »

Once had a similar problem with no obvious cause. Assuming your impeller blades were still intact as mine were they are supposed to be self priming. So took me a while to out of no other ideas I poured water from the outlet hose into the implellers/pump reattached hose and it worked just needed priming.

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mike cunningham
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Joined: Sat Dec 20, 2008 11:21 am
Location: Jacqueline, F30 #3, Discovery Bay, California

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by mike cunningham »

I had impeller blade bits make their way into the heat exchanger where the partially blocked flow. Probably not your issue but I would check impeller condition to be sure. May be blocking output port?

I have a 2gm and have never had to prime. I think that is because the pump is below the waterline on my 30, water gushes into the pump housing when seacock is open and faceplate off impeller. Don't ask how I know this.
Mike Cunningham
Freedom 30 (Mull) Hull #3
Build date...June, 1986 . Freedom Yachts USA, sloop, shoal keel
Gun Mount and pole retrofitted (purchased from a Hoyt Freedom 32)
Yanmar 2gm20F , 1600 hrs fixed two blade prop
e-rud and ocean racing equipment

richsailorman
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Joined: Mon Oct 04, 2021 6:16 pm

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by richsailorman »

Hi Mike,
Thank you for your reply.
I will be going back to the boat this afternoon and inspect the impeller.
Best,
Rich

richsailorman
Posts: 7
Joined: Mon Oct 04, 2021 6:16 pm

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by richsailorman »

AlanK wrote:
Mon Jun 13, 2022 3:38 pm
Once had a similar problem with no obvious cause. Assuming your impeller blades were still intact as mine were they are supposed to be self priming. So took me a while to out of no other ideas I poured water from the outlet hose into the implellers/pump reattached hose and it worked just needed priming.
Hi Alan,
Than you for your response, I will try your solution later today or tomorrow after checking the impeller.
Best,
Rich

richsailorman
Posts: 7
Joined: Mon Oct 04, 2021 6:16 pm

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by richsailorman »

AlanK wrote:
Mon Jun 13, 2022 3:38 pm
Once had a similar problem with no obvious cause. Assuming your impeller blades were still intact as mine were they are supposed to be self priming. So took me a while to out of no other ideas I poured water from the outlet hose into the implellers/pump reattached hose and it worked just needed priming.
Hi Alan,
I examined by impeller and it was in great condition. I opened the water screen and examined the screen inside which was clean.
When I opened the water screen container, the gasket sealing the top broke into pieces. I have a new gasket on order which I will replace soon and then prime the system as you did.
My concern is that there might be an air leak in the system, and will test the system for air leaks before it is primed.


Did you ever lose the prime again after the first time it happened?
If so, were you able to track down the cause of losing the prime?
Thanks,

Rich

AlanK
Posts: 127
Joined: Wed Dec 10, 2008 6:59 pm
Location: Freedom 33 Boston, MA USA

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by AlanK »

Only had this happen once. I believe it happened after a winterization when launching in the spring. It’s possible it ran dry briefly when I was running anti freeze through.

richsailorman
Posts: 7
Joined: Mon Oct 04, 2021 6:16 pm

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by richsailorman »

Hi Alan,
Thanks for your reply. Glad to hear it was a one time event.

I checked the impeller and it was in very good condition. I put a wee bit of silicon grease around it and buttoned it up.
The water screen cork gasket above the screen cage, came apart upon removal. I ordered a new one nd installed it.
Checked all the hoses, filled the water screen with sea water as well as the hose to the the seacock and the hose to the water pump.
The engine started right up and water was shooting out of the exhaust pipe.

The next day I tried the engine again and all is well.
Thanks for your help.

Best,
Rich

AlanK
Posts: 127
Joined: Wed Dec 10, 2008 6:59 pm
Location: Freedom 33 Boston, MA USA

Re: Perko 493/500 water strainer blocking flow to water pump?

Post by AlanK »

Glad to hear.

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