Volga with Mercury Outboard

What engines to use, how to fix them, gasoline/diesel, etc
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Location: Mönchengladbach - Germany

Volga with Mercury Outboard

Post by olaf » Tue Oct 30, 2018 6:15 pm

This year I finished the renovation of my volga so far that I could drive it first time after three years of renovation.
I build an open boat with the cockpit in rear of the cabin. The original engine was not in the boat when I bought the hull.
So I had the possibility to install an inboard again or to use an outboard engine as the seller did it. He used engines up to over 400 hp. Because of the completely missing power transmission elements I decided to use a outboard again.

I wanted to set the boat on a trailer. So I can be flexible in using it in different areas if I could make it slipable.

For that reason I had to build a bracket for the outbord. The one which was installed by the previous owner was unusable for my objectives. But the stern of the boat was already destroyed. So I built a new constuction.

Regarding the engine outbut I read about the original engine that 70 hp should be enough to bring it out of the water and reach (so the documentation said) for a speed of 70 km/h or nearly 40 kn. But the propellor has a relative steep angle which I can not reach with an outboard engine. So I thought I need more power and the engine must be continuously adjustable because of the trailer.

I bought an Mercury EXLPT 115 hp and installed it at a hydraulic bracket.

This summer I first tested this constellation at the medditerranian sea in Spain. At arround 20 km/h the boat came with the front wings out of the water at 3500 rpm if I remember right. If I then got it to 4000 rpm the boat got a little push and came full out of water. The speed rose up immediatly. The maximum speed was 65 km/h or 35 kn. May be with an other propellor I can reach higher speed. This I will try next year. The consumption of fuel was as the SC100 instrument showed and as I proved at the patrol station at appr. 1 ltr. per nm.

But I think the boat is not built for open sea. A comfortable cruising only was passible until 10 or 11 in the morning. Then the thermal winds came up and the began to became more rough. The waves grew up and were relativly long so that the boat more and more went over the first wave and dipped the bow into the next wave. That behavior slowed the boat down in way that made no fun. Second thing was, if the waves came athwartships the boat has no stability and it was not easy to drive. For that experience in the furtue I think I prefere the inland waterways.

Would be interesting, which experiences you have.

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