Saving Old Seagulls

Back story: Even though I get a steady stream from the weep hole once rpms get up above about 1000rpm, it was intermittent when first running my "new" motor and I wasn't sure if there was some minor blockage or cavitation in the water barrel interfering with water intake. So, I set out to investigate as time permits. After much reading through all the excellent info on here, I decided to try dropping the exhaust tube first and checking for water output up through the water tube. No joy there. Couldn't slip the outer tube down, even with a rubber pad and large pipe wrench to try and twist it. Deliberately left the securing screw out and pondered dropping the water pump instead to check it for built up crud. Both screws loosened without much fuss and I left that for next opportunity to work with it.

BTW, opportunities occur here when (a) the heat index is not 100 or more ; and (b) we are not in a big lightning storm.

Next chance, I back flushed again in both directions with an aggressive little cone shaped garden hose nozzle and poked around in the weep hole with a small probe. Got a little oily rusty grunge, but not much nor any real flakes. Put it back in the water barrel to run some more.

Now to applying heat. A trick that works great on old BMW airheads like my R80 for loosening the large finned exhaust header nuts from the head is simply start the motor for about 60 - 90 seconds to heat the area. The finned nuts let go easily whereas cold they are tight enough to risk breaking fins off even with the specialty wrench that hold several fins at once.

And that was why I left the screw out of the exhaust tube. Ran the motor for five minutes or more watching the water stream come and go with changes in rpm. It was better than before and pretty strong at higher revs. Then as I suspected/expected, the hot exhaust tube suddenly blew loose and slid down onto the gear case.

Sooner than later I plan to pull the cylinder head and clean out the water passages because even though the cylinder head never got hot enough to sizzle the water drops on it, the water discharge did get steamy a few times if it diminished to a trickle or stopped. First, I'll try the head bolts cold. If they are stuck, I'll bring the motor up to temp and check again. If it doesn't work, next step will be using a 1500 watt heat gun in addition to warming the motor up. If this works as I believe it will, I avoid burning any paint using a torch for applying the heat.

You might find some interesting reading in this link about water cooling at lower throttle speeds....

viewtopic.php?f=2&t=4720&p=37926&hilit= ... low#p37926

Thanks. I read that and some other posts regarding rpm vs water flow. So I didn't panic after having read about the rpm threshold for the water pump to lift all the way to the power head. I don't plan to add the siphon tube since I won't be at idle speeds very much. And pulling the head will happen "someday" as I feel the need more strongly based on observation and monitoring the motor's cooling.

The seller had acquired the motor from his uncle who purchased it new and estimated between the two of them the motor has about15-20 hours on it. It has been idle for a while but appears well treated.

I'd be surprised if there is much of a blockage if any in the water passages in such a low hours motor. It would be worth bringing it out on the water to see how it copes in the real world and not in a barrel, before stripping it apart. Did you have the propeller on or off when running in the barrel?

I totally agree and plan to get it on the boat and on the water before tearing into it further. My barrel is one of those big blue plastic 55 gallon drums. I could affect the water flow just by turning the motor left, right, and center with the best flow with the motor centered. So the barrel definitely has some impact on water flow into the motor.

Looks like another 4 days or so to get a good weather pattern to sail early in the day and get back on the trailer before storms form in the afternoon.

We alternate between a strong easterly sea breeze some days which push thunderstorms inland, and a predominately westerly flow across the whole state that brings the sea breeze all the way across from the Gulf of Mexico and fires up storms over our area which is the Indian River Lagoon System within two miles of the Atlantic beaches. Either pattern usually sets up for 2 - 4 days at a time. Even though some days are a washout, the good days with the easterlies make it easy to travel quite far up or down the lagoon on a reach with seldom a need to tack.

Motoring is for getting in and out of the launch basin close to my house. Or rarely being totally becalmed for a while.