repower

[toadfish]

I have a 1986 18' Seacraft with a 1991 Mercury 200 offshore engine on it. The engine was on the boat when I purchased it and had a seized piston due to an oil injection problem. I too looked long and hard at re-powering with a smaller engine. However, I found that some of the smaller engines (175, 150) are actually HEAVIER than the 200. I don't remember the exact weights, but I spent a lot of time on the NADA site. Someone also told me that the 200 v6 block is the same one used on mercury's 150 and 175. The only difference is the bore, and some electrical. Anyway, I decided to re-build the engine myself and removed the old oil injection system. It is now a pre-mix engine and has been running strong for about 3 years. While I will agree that the horsepower may be a little much, the weight does not seem to be a problem. I rarely drive the boat more than a good cruise speed, but it is nice to have the extra power if you need it....Toadfish

[Fr. Frank]

The 20' Seafari is even heavier than the CC, and will run just fine with a 115. My first Seafari was a 1973, 1830 lbs hull weight, dealer equipped with a '74 115 Mercury. Cruise was about 24-25 mph, top speed was about 29-30. I repowered with a '77 1500XS which gave me a cruise of 34-35, and a top speed of 45-46 mph.
My current Seafari is a '72, hull weight is 1870 lbs, and I got it with a 1972 Chrysler 120 hp. It planed easily, cruised at 22-23 mph, and had a top speed of 26 mph. I installed a 1991 Mercury 150 XR4, with the big gearcase and a Bob's nosecone. Top Speed light on fuel with just me is 46 kts on the ol' GPS, which I think is about 51 mph. Cruise is 34-35 mph, just like the 1500 XS. I have a higher top end with the V6, but not significantly higher. The real beneift is that the XR4 is better on fuel.