Seafari 25 Power/Drive Options

[gjkailua]

I was wondering if anyone could give me some advice as to what type of drive system to use with my boat. We previously used the boat for some testing. We ran it with a 440hp yanmar/sterndrive combo as well as with a single 250 hp outboard. We got about 45 kts with the diesel and 34 with the outboard, but neither combo realy felt right for the boat. I was thinking about putting about a 315hp diesel with a sterndrive. I have heard that some people prefer a straight shaft or V-drive configuration for these boats, but I have never heard why. Any opinions or past experience would be great.

Thanks for the help.

[nestorpr]

I don't think a straight shaft would work in this boat since the engine box would probably sit between the helm seats, unless you convert it to a center console so the engine is under the console but perhaps a v-drive would work. I don't know if any Seacrafts are so equipped now but a good source of info is on 25Bertram.com, there are many dual engine v-drive boats in that forum with a lot of info, I'm sure you can adapt the dual engine info to a single engine. I myself like the diesel I/O setup but I understand that's a very personal thing. The good thing about the v-drive is that it gives you a ready-made platform (the engine box) to lean against while fishing or sit while underway.

[ScottM]

As Botapeje mentioned, a straight IB may not work but a V-drive could. A few of the 23 Sceptres were set up with V-drives but they also have a tunnel cut into the keel. Perhaps you could go straight out the bottom on the 25 Seafari but if you had to put a tunnel/prop pocket in that would be a lot of work. Mark Rattenbury from this site has a Sceptre V-drive so he will probably comment on the subject.

[Water Rat]

gjkailua,

I think it will be tough to get a lot of first hand data due to the limited number of 25' Seafari's out there and the small number of 25' owners on this board. However, I would be very interested in knowing more about your 440 Yanmar/outdrive combo. - as I am thinking about a disel repower for my 1978 23'Sceptre repower. For what it is worth in comparing my boat to yours, and from what research I've done, I would think the 315 diesel i/o (single) would be a good fit. I've got a single 7.4 litre/Bravo 1 (330hp) now, and believe I would get slightly better top-end, much better cruise (speed and efficiency, obviously) with the 315 Yanmar/MerCruiser Bravo 3 package. Benefits comapred the the 440 Yanmar are somewhat smaller block, no need for a separate transmission. Also, look at the Volvo packages (D4 DuoProp at 260hp and D6 Duoprop at 350hp), though these are somewhat heavier than the Merc options. I also have not ruled out twin outboards on a bracket, a la Doodlebug's setup (see pictures in the photo section from the Anclote Key gathering). Also, if it helps, you can see my boat (Chris Downey's 23' Sceptre) in the gallery section here. As far as pwering with what "feels right" for the boat, this is a big concern if mine as well. My boat was originally made (and designed ?) for either single or twin outboard (transom mount), single and twin i/o, and also inboard. The 25' Seafari, to my knowledge, was only offered with single and twin i/o options. I've seen some interesting things, though, including a twin yanmar diesel i/o in a 23' Sceptre (I have pcitures, need to scan and post).
If you wouldn't mind, I would be very interested to learn more of your Yanmar installation. Also, please feel free to ask if I can be of any help. Last, there was a 23' Sceptre owner on here who did put a Yanmar 315/Bravo package in his boat - just can't remember his name right now but will look for it.
Good luck, Chris.

[1bayouboy]

Is doodlebug's the blue CC or the yellow Sceptre...???

[Water Rat]

I believe the yellow Sceptre.