20 seafari engine options

[bilgerat]

some day My 84 merc 75 will be in need of replacing and I was wanting to go 4 stroke, will the 115 merc 4 stroke be too heavy and will I need to plug the scupper holes in the floor? what kind of performance should I get, Im running 34mph now with the 75

[BigLew]

Check out Fr. Frank's and many others. He is running a merc 90 and others have put much larger engines on as well. I believe I have read some as high as 175 or more.

[Fr. Frank]

I have seen everything from a single 70 hp Johnson, to a 250 hp Mercury on the back of a Seafari. I have rigged single 85's, twin 70's, and single 175 Loopers.

I used to run a Mercury XR4 on mine that put out about 190 hp on the hydro-dyno. Economy at cruise was 3.5 mpg or so, with cruise of 28-30 mph, and WOT of 53 mph.

I currently run an '06 90 Optimax (mfg date of 04/06), and I really like the 5.1 mpg economy at cruise, and the performance is adequate, cruising at 25-26 mph, with WOT of 34 mph.

I would ideally like to put a Hermco Bracket on my boat, with a single 200 hp Mercury Verado 4 cyl (518 lbs), or a single Etec 250(520 lbs).

I read a test which showed the 200 Verado 4 cyl. producing 219 hp on a dyno, the 250 6 cyl. Verado making 255, and the Etec making 248 hp. The Etec is considerably less $$.

There's an '89 Tracker SC 20' cc in this area that is running an aluminum full flotation bracket with an '08 30" 250 Etec turning a 22P PowerTech 3 bl, and he claims a top speed of 55-56 mph, best cruise of 30 mph at 4.3 mpg, and at 40 mph getting 4.0 mpg. If true, those are very good numbers. He said that with the BRP prop the motor came with, he could reach 60 mph, but only got 3.6 mpg at best.

[bilgerat]

Im not to worried about top speed, just wanted the dependability and quietness of the 4stroke, I was worried about the weight, My boat sits low in the water now with the 75 4 cly and the 8hp kicker on it so I was woried about the water level in the floor scuppers. I wont have the $ to put a bracket on unless I find a deal on one, I am planing on raising the transom hight when I put the new transom in this winter and going with the 25" motor and moving the kicker to the port side to level the ride .

[Bushwacker]

. . . just wanted the dependability and quietness of the 4stroke, I was worried about the weight.

Sounds like you want an E-Tec! At 30 mph, mine is quieter than a 4 stroke because it doesn't have to rev as high! Plus it's about 50 lbs lighter than an equivalent 4-stroke, so boat is better balanced and rides better! Cruise fuel consumption is maybe 10% higher than a 4-stroke, but trolling speed fuel burn is as much as 50% less on the E-Tec, so overall fuel consumption is about the same. Compared to my old 90 hp-at-the-prop carbed motor, I'm now cruising about 5 mph faster and using about 40% less fuel!

BTW, the 25" transom height won't help the water level in the scuppers!

[McGillicuddy]

I think Fr. Frank and Bushwacker are steering you right with a DFI 2 stroke. The E-tec 90 is about 335 lbs in the 25" shaft. That will be the lightest, most reliable, quietest option out there. I'm seeing new old stock for about $6500 w/3yr warranty. As far as fuel economy it is probably second only to Fr. Franks Optimax 90 but 40 or 50 lbs lighter. Since you are re-doing the transom, definitely raise it and go with the 25" shaft. I have an old 115 Merc on my Seafari and am pleased with the performance, but desire more economy.

In my mind the ideal motor is a 115 - 130 hp E-tec or Opti that weighs 50 lbs less than they actually do.

You will still get wet feet when you stand in a corner pulling on a fish but plugs or the "vortex" will solve that.

Scrap the kicker - you won't need it with the E-tec. They'll idle at 500 rpm and probably get 7-8 mpg at that operation.

Unless you opt for a much heavier motor, scrap the bracket idea. I don't think it benefits you in your stated application.

If you're really set on a 4-stoke, the Mercury 115 4-stroke is only 400lbs but I think It will leave you wanting on the holeshot and not really have any advantages over the dfis.
just my .02

Good luck with your decision.

[bilgerat]

vortex???????
I was looking at the Yamaha 4stroke 90 or 115 but Im thinking they are too heavy . The 90 weighs 380lbs and the 115 weighs 412lbs

[McGillicuddy]

Most 4 strokes in the 115 hp except Honda and maybe Verado will be in that weight class but I don't think that is a deal breaker. The Yami, Zuke and Merc are all within 10 lbs. or so. 400-ish most guys will agree is the high end without a flotation bracket. The boat was designed for a 300lb motor and a single battery

Eliminate the kicker (- 75 lbs), move your batteries forward of the fuel tank (- 50 -100 lbs) and go with your 400# 4-stroke. Shouldn't be that big of a difference. Just put real light stuff (maybe life preservers) in the stern lockers.

The "vortex" is a check valve for these through hull scuppers often discussed here. Basically imagine a the finger of a glove with the tip and base cut. It is attached (glued) at the top of of the scupper and inserted through the scupper so it dangles 3/4" below the hull. When the water tries to come up the scupper, the water pressure forces the glove finger to close stopping the water from rising into the cockpit. It is also known as a duck bill valve. Simple, cheap and effective. While making way, the water draft allows the glove finger to open allowing the cockpit to drain through the scuppers.

Do a search for "vortex" and you'll see several variations and adaptations. Set time period for like over 1 year less than 5 years.

csicknick has a 430lb 140 Zuke on a Seafari and he's way outside killing GBFT

Also check out scupper repair threads as this is a very common problem leading to water seeping into the bilge. But as the resident Bilgerat that may already be familiar territory

[eggsuckindog]

Etec - 130 or 150