Best Power Option for 74 Sceptre 20 OB

[ssscotty]

Greetings, first I would like to thank the moderators, senior members, etc., for this site and the helpful advise I have received. I have been a fan of classic SeaCraft for some time and always dreamed of owning one. finally this year I was fortunate enough to buy a SeaCraft. now im a proud member of csc.

With that said, as I get used to her I have questions as I am always trying to improve safety, functionality, and performance. have a 2001 Johnson 150 ocean pro which is definitely enough power. my issues at this point is weight in the stern and fuel efficiency. I love its performance, but at slower speeds the stern sits too low for my liking and forget about if someone is back there. with just me and my dog it sits a lot better, even feel comfortable to leave the scuppers unplugged. I believe my motor weighs about 380 lbs and I have 2 batteries back there. I do plan on moving them to the front consoles eventually. was thinking about repowering with either a slightly smaller 2 stroke, or a more smaller 4 stroke. think im currently getting about 2 mpg but definitely not more. will I gain fuel efficiency with a 4 stroke? will it still be peppy enough ? if I drop to a smaller 2 stroke will I gain fuel efficiency without loosing much in performance do to the lighter weight? of course with the 4 stoke less smoky and quieter which is nice.

any thoughts will be appreciated....? thanks

[McGillicuddy]

Yes you will double your efficiency w/ a 90-115 hp 4-s and likewise with a direct-inject 2-stroke. The huge difference at cruise speeds and the miserly fuel use at idle or trolling speeds is just amazing. For me with a 115 in. 20 w/ a 30 gallon fuel tank, it's about doubling your range at cruise, and easily tripling if you are just trolling or hunting all day. if you're low on fuel cut her back and still get home. Etecs, Optis, and tohatsus in 2 stroke, New mercury, suzukis and yammie 4-s. Like terry says, pick your color...they're all pretty good in that size class. Prop them right and they will all be peppy enough.

[Terry England]

Originally Posted by McGillicuddy

Yes you will double your efficiency w/ a 90-115 hp 4-s and likewise with a direct-inject 2-stroke. The huge difference at cruise speeds and the miserly fuel use at idle or trolling speeds is just amazing. For me with a 115 in. 20 w/ a 30 gallon fuel tank, it's about doubling your range at cruise, and easily tripling if you are just trolling or hunting all day. if you're low on fuel cut her back and still get home. Etecs, Optis, and tohatsus in 2 stroke, New mercury, suzukis and yammie 4-s. Like terry says, pick your color...they're all pretty good in that size class. Prop them right and they will all be peppy enough.

A Brilliant Perspective from a Seasoned Sailor!!

A word of caution about BRP - they lie like Hillery and cheat like Bill, the 90's make 101 HP and the 115's make 129 HP, those stinkers! Zukes turn big wheels like Proud Mary and Yamies spin along for years like sewing machines. Merc has a super-simple 4-S 115 that seems to be good so far. Tohatsus are commercial motors on the rest of the planet. Everybody has a pretty good motor in that size range. Be sure to add any required scheduled maintenance costs for the warrenty to the projected fuel savings and a gallon of the $40 oil to every 100 gallons of gas you will buy for the 2-S.
They all require "Pristine" fuel whereas the Johnson 150 will ingest beer cans and cigerette butts and keep going!
It might be difficult to justify the cost of an engine vs. the possible fuel savings - especially if the 150 is working OK.
We can't rescue you from a bad economic decission even if you have an EPIRB!

[FishStretcher]

Figure on 35 statute mph with a strong 90hp. And cruise at 23. An older etec 90 is pretty light. Not sure many 4 stroke options are lots less than 370 lb. I have one but if you are at 380 lb now, I'd move batteries forward first. If you do fiberglassing then I would foam core the fuel hatch, too. Those are labor intensive ways to fix static trim that are relatively inexpensive.

If I had the money, I'd change from my Yamaha F100 to an etec 90 or look at that mercury 115 four stroke.

[DonV]

What was the transom height? I missed that I guess.

Here's an option...

http://www.mbcforum.com/showtopic.ph...last/m/1/#LAST

[GameOnSalmon]

I have the exact same boat. I ended up putting on a 1994 mercury 200hp that weighs right at 390 lbs. I moved all my batteries up front into a step up box, i have 3 batts that i made. Dead center of the boat between the 2 windshield storage boxes.

I a still messing with Propping and engine height at this point. The new Enertia 16p Should be here in a couple of days. Right now i am turning a 17p mirage plus at 5200 rpm and i am 2.5 inches high with the 4" setback jack plate. I plan on raising another inch and with the 16 enertia should make 6000 RPM at sea level a 17p would be perfect. I am at 3500 feet elevation.

At the end of the day... what is it you want? You can go with less power and better economy or bigger power.

Hope that helps...
Robert

[flyingfrizzle]

I am re-rigging a motor as we speak (reeding actually) on my 74 20' sceptre hull. Started with an inboard to a bracket outboard. I put a heavy 225 3.0 mercury on it first and now have 2.5 200 that I am rigging. Should be more than enough motor and still pushing the weight but with the forward weight on these models you can get by with more than what you can on a cc model. The 225 did 65+ and was scary at those speeds so a 115 would be a great economy cruse motor if you are not speed hungry. Try to stay under 400lbs and maintain the best balance possible. I will report back more if I can get my new motor rigged this weekend. It is an 07 power head that I just had new rings installed in. Should be a nice ride with a top of 60 plus but what I am after is a cruse speed of 40-45ish at 2/3 throttle. I can hit it to out run a storm if needed and pull back and still have a good moderate speed at half throttle if wanted also. Might not be the best fuel economy out there but I don't make far runs in my 20' anyhow.

If you are happy with the 150 now and wanting more economy and are not worried about loosing a little speed like mention any of the smaller motors will do great, I would love to try one of the new mercury 115's If I had the coin to buy new. If you go four stroke just watch your weight. If you go 2 stroke you should have no issues. With your model, im surprised you have issues with the 150 now. Even with the bracket and heavy motor on mine I was surprised how well it did. I needed lighter but a 380'lbs Johnson on the transom if you move the batteries up front and shift your tank forward you should not have any issues. I would check to make sure you don't have any water weight in you foam. If you do, drill some holes in the low points and let it drain out. That sometimes makes these hulls sit lower than wanted. The sceptre model seems more able to handle the larger outboards than my cc of the same year did. My 74 cc hull had wet foam and I think I took out 800 lbs when I removed it.