repower

[Dunk]

Blackfin, this is my first post here. Jason asked me to add what I can...

That 150 Yams is a butt kicker from what I've seen and it's probably right at the 10% max(NMMA)165hp at the prop.. But I'm not a 4 stroke guy nor am I fan of Yamaha's. Although that Yam is the one I would recommend if you are dead set on a 4 stroke. That 175 Merc on that boat was the perfect power. Light and plenty of guts. But remember in 1976 the only V6 on the market was the 200hp Johnson and that was it's first year. So, that 20ft seacraft was designed for 300lb V4 OMC or 6 cylinder inline Mercs.. If I was repowering that 20ft Seacraft I'd be looking at a 175 Evinrude DFI. That 150 Yam is a strong engine, but it won't stay with a 150/175 Rude for the simple fact the Rudes are V blocks and produce more lower end torque. It's safe bet that Bomb will offer the 7yr warranties for the boat show season. The last two years it's been Jan 15 till Apr 15. Anyway you cut it Seacraft's are heavy deep vee's and need horsepower to move them. A 175 Evinrude comes in as close to that 175 Merc weight wise as you can get at 427lbs for a 25" engine. Somehow I just don't see a 140 Suzy moving that boat at 40mph+. Even if it would once you put 3-4 guys on it and gear/fuel the party is going to cave in fast. Getting a load like that out of the hole is a V6 job. Even a 135hp Evinrude will run circles around a 4 stroke 4 cylinder 140hp engine and especially out of the hole. Even if you are not looking for top end you want an engine that doesn't need to fight to get the boat on plane.

There's a guy around here with a 225 Johnson on a 20ft. You guy's are right....it's way to much weight. The SOB will run 55mph, but it looks half sunk sitting in the water. I've also got a buddy with a 75' 20ft with an 87' 120hp V4 Evinrude(looper). It's nice setup. The engine weighs 360lbs and it will run 35mph with 3 big guy's in it..cruise at 26-28. In any more than 2-3ft seas you can't run more than 20-22 anyway. The 135 Rude DFI's are rated 148hp at the prop according the Bass&Walleye magazine test. Everyone's 150 is 165 at the prop or they wouldn't survive the bassboat circuit and you can figure the Bombs 175 at about 190 at the prop. Everything we're talking about here is about a dead heat on fuel consumption at cruising speeds.