Fresh water strainers

[BlueSkye]

There's a lot of grass in our river this year, and sheared off pieces of it floating in the water. I got a plugged cooling water intake on one engine while going through a pair of big locks. Overheated that engine and shut it down when blue smoke billowed up from the exhaust. I tied up to the canal wall to let the engine cool off and assess. The external engine temp registered 240F with my handheld laser. The water pump was toast. Engine cranked and started. Sounds like the rubber muffler is damaged as well. The engine paint is not discolored. The sherwood water pump is. All the fingers on the pump impellers were gone, ground into little pellets.

I couldn't clear the strainer from inside the boat. It is the original dished plate with slots cut in it, mounted on the underside. I am only assuming it is plugged with grass at this point. I don't have strainers inboard. I had some hose so I tied in to the other engine intake with a tee I had put in for winterizing. A quick replacement of the sherwood impellers made the water pump run. Needs a new shaftseal though, water was spraying. Anyway, it got me the last ten miles to my home port with both engines. Haulout will answer the grass question. This old guy isn't anxious to dive if it can be avoided.

I would like to make this part of my setup more bullet proof. At least I need an alarm on the temperature. The gauge worked but I wasn't looking at it. I might have been able to clear the strainer from inside with some kind of back pressure but I didn't figure a way to do that in the moment. It probably wouldn't have happened if I shut down the engines while the lock was filling. Everything in the water is violently agitated during that.

First time I've had this sort of trouble in twenty plus years of cruising the Blue Skye. Anyone have a similar story or comment?

[jralbert]

No strainer tales here...but just a note to say you really got put through the mill in, so far on this board, a unique situation. Never described as you did before. COngrats on your ingenuity in bypassing. I've been out of boating for a long while and may be dreaMING Something that didn't exist but remember having a temp alarm you could not miss. It worked, I think, as a relative to the oil pressure alarm. And if I did dream this, I would bet there's an inexpensive alarm system available.

[BlueSkye]

Here is the ooze that killed engine #1.

[Fastjeff]

Watch out! Something like that cost me a good motor (and $4,000).

It's imperative that you remove (from the motor) and test your high temperature switches (one wire) every year or so, for if they fail.... All you need is
a bucket of boiling water and a voltmeter; the circuit closes at ??? degrees.

Jeff

[BlueSkye]

So far it looks like the only thing toasted is the Sherwood water pump. Maybe the muffler.

For anyone who has not seen the inside of a Sherwood pump, here's one of the toasted impellers on the left, a spare on the right.

My engines didn't have a temp switch. They will in future. Fortunately, I looked back and saw the exhaust smoke.