Sr SQ
Well-Known Member
Is that a planing hull? What's your top speed and burn?
Thanks for the answer.
Many boat & O/B mfgrs have "prop test info on their web sites. Most boat mfgrs bundle with Yamaha power, so info on Yamaha is the most widely available. I just repowered with twin 300 G2 ETEC's. The shop owner had twin 250's on his 28' well craft as a free promotional deal where he had to sell them every year. This deal ended when BRP stopped making OB's & he replaced them with twin 300 Yamaha. Dropped 5mph in top end & suffered a 20% drop in fuel consumption. I am going to venture that loss go torque (2 stroke versus 4 stroke) on a heavy boat is at play here, so a motor with larger displacement & longer piston stroke would win here (not all 150hp engines have equal power curves & good luck trying to get this info UNLESS it make that mfgr look better than the rest.
I have a 33' chriscraft that probably weighs 13000#, and before the OB's I was leaning towards twin diesels. I spent a lot of time using the prop calculator on www.boatdiesel.com where you can model boat speed/mpg/etc. The biggest factor is weight, followed by hull design (deep/shallow V). achieving the same HP with twins versus a single didn't matter a lot; more like 5%. If you run in rough water, having twin props will result in less RPM drop than a single prop, so economy with twins might be better. If you are considering a boat with around 300 HP which SHOULD be at least 25' long, twins with an autopilot & trolling on 1 (or 2) would be IMO the absolute best combo. My chris hits 40MPH & idles at 3 MPH in dead calm water on 2 engines; 7 MPG at 8mph on twins. Furuno makes auto pilots with a handheld remote & Sabiki mode (keeps you headed into the seas when in reverse still fishing).
As said, it all depends on the hull.........
Did the mfg design the hull for the weight of twins, weight, style, beam, length, typical sea conditions?
It will cost you more to run twins........how much more, that depends on the hull and its use.
I prefer the twins for west coast ocean fishing but on a bass boat on a calm lake a single would be a better fit IMO
I am a twins fanboy after running one and 1/2 dozen singles, I will never deal with a kicker and all its shortfalls again, but that's me.
With todays mid size 4cyl OBs troll fuel burn vs a kicker is negligible and new kickers with trim/remote/etc are 1/2 the price of a new 150.......
Its hard to explain the handling characteristics, , but the're very noticeable. In rough seas the twin props feel like a 4 wheel drive in the snow similar to trolling on the 150 vs the 15.