'81 H27 Raw Water Strainer Location

[SailormanDan]

Hi,

This will sound like a newbie question, but I have an overheating Yanmar 1GM motor and other posts suggest cleaning the raw water strainer as a first step.

Where is the strainer located? Is it out on the hull and only accessible if you haul the boat, or is it in the bilge below the seacock? If outside, can I reach it with a brush on a long handle and be confident I got it cleared?

Thanks,
Dan

 

[cbsailor]

On my previous H27, the thru-hull strainer was just forward of the engine and had a 1/2" ball valve attached. Cleaning while in the water was accomplished in one of two ways. The first involved removing the hose off the nipple attached to the ball valve and then opening the valve and jamming a long screwdriver down thru the valve into the strainer and scraping around to remove any blockage. You had to be quick as water does come into the boat. This way does not clean out the intake grooves of the strainer, but will usually be good enough to operate for sometime.

The second way called for a dive overboard and a scraping out the blockage thru the grooves of the strainer. Tihis way sometimes called for also doing method 1 to clear growth out of the nipple section of the strainer.

 

[SailormanDan]

Thanks, I guess I have to do both once the water warms up. Sounds like the starting point for troubleshooting.

 

[David in Sandusky]

Great Picture

That's it.

And now I know how to clean it while it's in the water.

Of course, it's never been blocked in 10 years on Lake Erie, the Detroit River system, and Lake Huron.

But I think you salt water guys encounter lot's more stuff in the water.

 

[Don12364]

And then again I removed the end of the pipe from the engine and made a makeshift connection to my dinghy air pump held above water.
Turned on the valve and pumped like billy oh.
Lots of bubbles and a nice little plug of weed went floating by.
Worth a try before doing anything else!

I now keep handy on board a short ready made up length of plastic pipe of suitable diameter to match both the pump and the boat's tube diameters as an adaptor.

 

[garyc]

I would check water pump first. disconect water inlet hose from engene put into bucket and open valve. I f water is flowing you know it's the pump. Good luck

 

[Ed Schenck]

I'm with Gary. Check the flow first. And then don't you also have a strainer between the seacock and the engine pump(bottom left in picture)? If the water flow from the seacock is good then check that strainer. Have you checked the pump impeller?

 

[cbsailor]

There was no strainer in the engine compartment on my 81 H27. I believe the picture below shows it in near factory original setup. Raw water cooling on the 1GM was a hull strainer pickup coupled to a valve (originally a gate type when I got the boat) and hose to the pump. Pretty basic setup.

 

[Ed Schenck]

Strange that the strainer would have been standard equipment on my 1979. Never knew a boat not to have one. Chances are your water pump impellers get chewed up pretty quickly.

 

[cbsailor]

I never had an impeller chewed up in the 10 years I owned the boat. I did have a couple of impeller rubbers seperate from the metal centers. A New impeller was installed every year during spring commissioning. Old impellers were kept as spares and a baggy full of them went with the boat when I sold it.