What is this *thing* between my raw water intake and engine

stantale · #1 (**permalink**) 09-04-2011

Hi All,

first off, happy Labor Day!

Second, what is this thing? I have a yanmar 3GM30F - it sits right on the engine raw water intake thru-hull, and from it goes directly to the engine. No wires or any other hoses go to/from it (Although one wire seems to be cut off, might have just been a grounding wire?).

If it's some kind of filter, what type of maintenance does it need?

The reason I don't like it is that is long and big, and exerts tremendous pressure on the thruhull if knocked since it's bolted straight on.

Any help is appreciated!

-stantale

PorFin · #2 (**permalink**) 09-04-2011

Stan,

That's an intake strainer (at least the part between the seacock and the football-shaped thing.) You need to open it up regularly to clean out the strainer basket. First, close the seacock. You get into the strainer by loosening the screw/nuts on the top of the bail -- that u-shaped bracket -- and roll it out of the way. The lid can then be removed and the basket pulled up and out. Replace the basket, reposition the bail and tighten it back up, then open the seacock.

I've got no idea what the football-shaped gizmo may be.

MitchM · #3 (**permalink**) 09-05-2011

is the football gizmo connected by a hose or pipe to drain into the raw water filter?looks like it in the picture ..
is the football gizmo able to be opened at its top by removing a cover or bleed bolt ?

if answer to both these questions is YES it may be a home built winterizing system that allows you to pour antifreeze in to the football and have it drain into the raw water filter to be sucked up into the engine ..

if football connects some how directly into the engine block -- we need to know that too..as that would not be compatible with a winterizing system hypothesis...

stantale · #4 (**permalink**) 09-06-2011

Thank you for the answers, very helpful!

This is the sequence for the football: it's all in a straight line, so water comes in through thruhull, through seacock, into the newly found strainer, into the bottom of the football, exits the top via a 90" adapter on which the rubber hose attaches which goes straight to the engine.

There seems to be a drain hole on the side (visible in the picture) or at least its a nut that is centered on the football.

There is also that black wire that is cut and just hanging down, I assume it's just a grounding wire.

Any new guesses?

If no one knows, I'll remove it - or just leave it and call it the football, raising my eyebrows ominously when someone asks about it.

PorFin · #5 (**permalink**) 09-06-2011

Quote:

Originally Posted by stantale

Thank you for the answers, very helpful!

This is the sequence for the football: it's all in a straight line, so water comes in through thruhull, through seacock, into the newly found strainer, into the bottom of the football, exits the top via a 90" adapter on which the rubber hose attaches which goes straight to the engine.

There seems to be a drain hole on the side (visible in the picture) or at least its a nut that is centered on the football.

There is also that black wire that is cut and just hanging down, I assume it's just a grounding wire.

Any new guesses?

If no one knows, I'll remove it - or just leave it and call it the football, raising my eyebrows ominously when someone asks about it.

Stan,

At this point, I think it safe to say that you probably don't need the football.

Here's a thought: Close the seacock and remove the (drain plug?) nut on the side to see what you find. It could be just a sacrificial anode/pencil zinc, located there for some reason that made sense to someone at one point. Since the grounding wire's not connected to anything, it's serving liittle purpose now.

eherlihy · #6 (**permalink**) 09-06-2011

The football looks to me like some kind of check valve....

Also, I would get rid of that raw water seacock & strainer & replace with one of these;

Tempest · #7 (**permalink**) 09-06-2011

I was initially thinking some kind of winterization..that allows you to add Antifeeze and/or run the engine when out of the water. The Plug seems a little small though..years ago... I had a T set up that accepted a garden hose..

jackdale · #8 (**permalink**) 09-06-2011

Quote:

Originally Posted by eherlihy

The football looks to me like some kind of check valve....

Also, I would get rid of that raw water seacock & strainer & replace with one of these;

While you are replacing it add a loop in the intake hose that goes up above the waterline. This can serve as an anti-siphoning loop. That makes it a little less scary when you have to open the seat strainer to clean it. You still should close the thru-hull/

You should check this on a weekly basis. The glass allows to get a a view of the strainer. I have taken out algae, fish and weed.

redline · #9 (**permalink**) 10-14-2011

Could the football be some sort of vacuum switch? If the strainer plugs up and the engine keeps trying to suck water, there'd be a pressure drop right about there. Makes sense only if the hanging wire was not a solid ground but rather a switched ground. Have thought of adding a vacuum switch myself, "just in case", though it would be T'd off the intake, never inline.

Minnewaska · #10 (**permalink**) 10-15-2011

Was the football a flow alarm sender?

I've learned the hard way that they are prone to failure. Perhaps it was disconnected.