150 vs 175

[zach]

Don't need them, but you do want them. They make an already great ride better. You can bury the bow in chop if you need to or adjust the boat for your fat friends who are engaged in conversation while underway on the same side of the boat.

[Bushwacker]

Good to hear from a new Seafari owner! (PM me your e-mail address and I'll send you some brochures on that model and an engine comparison spreadsheet I put together.) You're going through the same decision process I did when I bought my Seafari, without an engine, in 1975! I went with OMC because the Merc's at the time seemed to have lots of corrosion problems in salt water. A friend of mine who bought a new Seafari with a 150 I-6 Merc is now on his 3rd one, the first two being replaced due to corrosion problems. This was before the V-6's came out, so the choice was between a 115 and 135 V-4, both 100 cu. in powerheads. I don't know how long you plan to keep the boat/motor, but I finally picked the 115 for durability reasons.

An old mechanic in Jupiter at Barden Boating Center (Now Jetty's resturant!) who supported the local commercial kingfish fleet, told me that a 115 would outlast about FIVE 135's! He said the commercial guys would buy a new motor every year, and they all bought 135's. He propped them for normal loads, but they'd go out and load up with 1000 lbs of kingfish, and then run back in at full throttle, which is about the only way they ever ran them. They started blowing powerheads, so he converted all of them to 115's, and they had no more problems. He said the 115's had enough margin to withstand that type of abuse, where the 135's did not. Top end speed difference was estimated to be only 3 mph. The 115's were a less highly tuned engine so they also idled better, started easier and were generally less temperamental. I ran that 115 (really only 90 hp at the prop) hard for over 30 years and about 1000 hrs with no durability problems. Made the 175 mile trip to the Abaco's 6 times with a very heavy load, cruising at 4500 rpm all day long at about 20 kts, with no problems. It was also a very light motor at only 300 lbs, so the Seafari was well balanced and rode very well in rough seas with it. When I finally decided to repower a couple of years ago, the old motor was still running fine, but I wanted newer technology with less noise, smoke, and better fuel consumption.

The only motors I considered were the E-Tec, Optimax and 140 zuke 4 stroke, because of weight. The Honda, Yamaha, and bigger Suzuki are simply too heavy for the 20' hull IMHO, especially if you want it to be self bailing! (The 20' hull was designed in the mid 60's when the biggest motors were about 300 lbs, so I believe that going heavier than that progressively worsens balance, min planning speed, and rough water ride.) The opti probably has the best cruise fuel consumption but I eliminated it because it's just as loud as the old motor. The Zuke seems to be a good motor, and lots of guys on the site seem happy with them, but it's only a 122 cu in powerhead, so I would expect it to be a high rpm motor and a little weak on mid-range torque. I ended up picking the E-Tec because at 155 cu. in. it's very strong on mid-range torque, and most of the milder (lower HP/cu in) E-Tecs seem to be under-rated by about 10% (it's REALLY a 165 hp motor per BRP's own brochure). I might have picked the 115 due to ~ 50 lbs less weight, but they were not in production at the time. As it turns out, the 150 V-6 is a very smooth, quiet, sweet-running engine that is actually a little quieter than the 4-strokes at cruise because it doesn't have to be wound up so tight. Fuel consumption is in the 4-5 mpg range at cruise; at trolling speeds, it runs 8-12 mpg, the most efficient of ANY motor, due the very lean stratified charge combustion mode the E-Tecs run below 2000 rpm. As for durability, I've had absolutely ZERO problems in 2 years and about 120 hrs and have only used 2 gal of XD100 synthetic oil in that time. Have only been back to dealer a couple of times for ECU software updates and I-Command gage problems (Stay away from the "Classic" analog-type gages; the digital ones made by Lowrance, although harder to read, are cheaper, easier to install and apparently trouble free.)

As for the 150 vs 175 vs 200 choice, the manufacture's association (NAEBM?) simply requires that the advertised hp be WITHIN 10% (+ or -) of the real number, so I suspect the real number comparison is approximately 165 vs 180-185 vs 195-200. Since I've seen 49.9 mph on the GPS on my rig with full fuel, but top down and otherwise light load, I've concluded that the "150" is plenty of power for the Seafari. Most guys probably think that "more is always better", but I'd be inclined to pick it over the 175 or 200 because it might be a little more economical and it's certainly lower stressed based the fundamental HP/cu. in. criteria. Don't know where you're located, but when offshore around here you can't often run the light 20' hull much over 20 kts without going airborne, so an extra 3-4 mph (over 50 mph) really wasn't that important to me.

I would definitely recommend trim tabs; I added them after my first Bahamas trip and they made the boat ride like it was 2-3' longer!