Working on the boat

When your dinghy engine make you feel dinghy!

By February 20, 2018 No Comments
My dinghy, Temptation

Back in 2014 I bought a new dinghy and engine for the Guiding Light. I got a Caribe 12″ RIB dinghy and a 25 HP Tohatsu to push it. You may be wondering why I got such a big engine, well that is because of my charter business. I wanted to be able to get up on plane when I guest and also to be able to pull them with an intertube (check out tomorrow’s POTD to see how fun it can be).

The problem started atthe begining of last season when I got the boat back in the water. The guy I hired to service the dinghy forgot about it and never flushed it out or changed any of the fluids, plugs, filters, ect. So by the time I got back to it the raw water cooling was clogged up and there was no water spitting out the side of the engine (although this is just a visual and most of the cooling water actually flow through the prop).

I spent the whole season with my engine limping along, even though I had someone take the lower unit off and try to squeeze acid up the intake. It worked a little bit and I continued to use a mild acid in the discharge to keep it flowing. The problem was that it never truely cleared and the sensor showed it was overheating and would shut it down. Of course my luck had the same thing happening this offseason with a different mechanic and it sat again.

This time I took matters in my own hands (with the help of a live aboard in Red Hook) and I want to share how I got the engine unclogged and running great again.

The first thing to do is take the lower unit off (simple to do with a couple bolts and a cotter pin) and make sure the impeller is working. You can set it down into a bucket and put a power drill on the rod and run it. Water should come spitting up. Check that works.

Next, take the thermostat out and see if you can get water to flow from there outthe discharge. You can do this with a funnel or hose and the water will come out the pisser or where the lower unit was. Check that works.

Third, try to get water to pass from the copper intake line that attaches to the lower unit up to the thermostat. This can be done with a hose and little hand pump ball (like on the fuel line). Nope. Houston we have a problem.

Now that I knew where the clog was I keep trying to get closer to it. First I took the power unit off and check the intake to the termostate and that worked, so I knew it was somewhere in the upper unit. By the time I was done I found it between the two plates that the power unit and lower unit attach to. At this point the guy helping want to just flush it with acid, but I descided that if we had the engine this torn apart we were goin to go all the way and find the problem. Once we gotthe last few bolts off there it was four to five inches of sand, salt, and yuck. Now that we found it all it took was a little pick and some water and presto it was unclogged.

The point of this blog is not to be a manual to fixing engines, but to give you some helpful ideas, encourgement that you too can do it, and if you are going to do something do it right the first time! 🙂

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