got a new to me boat

[scuba66]

i would go with four stroke . they are cleaner running. even if you have to do oil changes its still worth the investment. i have owned a 50 four stroke yamaha for 5 years, use it for commercial diving, recreational work as well and it has over 2100 hours on it with no problems. but do the oil changes!!! all of its use has been in salt water as well. servicing the anodes helps to keep the oxidisation down.

 

[Donnie1442000]

My personal experience with fuel consumption matches what Hank is saying. But that’s just what I have experienced. For a dive boat I would go as big as is safe. In the less then 30’ range you end up weighting the boat down to near its max with gear and people. If you go with the smaller motor you are working the piss out of the pour thing and it will consumer lots of fuel to keep you going. The larger motor while bigger is working only half as hard and in the long run uses less fuel. While few people agree with that it’s what I have personally found to be true. I will say though I’ve never been able to play with different motors on the same boat so it’s far from scientific.

Above all get what you can afford and have FUN!!

 

[jumpvideo]

Regardless of the motor you choose consider installing a Doel-Fin hydrofoil or similar product. You'll your Bayliner will plane faster and use less fuel. I ran boats for years and always doubted these contraptions had any benefit. Afterall, wouldn't the manufacturer modify the motor foot with similar foils if they actually worked? Apparently not. I operated a 28' Wellcraft with twin 150 Yamaha's for 8 years and installed Doel-Fins after the first year. That results were well worth the investment.

 

[Nemrod]

Not knowing the year of manufacture of the boat the data plates often have a max horsepower and a max weight. Pay attention to that. New engines are heavier than older engines, especially pre DFI two strokes from the early 80s.

Engines are now rated as continuous sustainable horsepower at the prop. I forget when the switch occured but in the past they were rated as peak instantaneous horsepower at the crankshaft.

We have a 150 Optimax on our BW and get up to 5.5 MPG. My parents still have an older Johnson 135 on a slightly smaller 18 footer. It consumes nearly twice the fuel and about four or more times the oil. It also is not 135 horsepower. Compared to the Opti 150 I would guess it makes about 100 horses. If it matters, it is also a smelly engine to run and clearly introduces pollutants into the ecosystem. The new two and four stroke engines are VERY clean running engines.

Good luck with the boat.

N

 

[DennisS]

I'm a luddite when it comes to marine engines. I have two 4 cylinder straight inboards on my boat. I can fix it with a pair of pliers.

An older OMC Evinrude/Johnson can be rebuilt by anyone that can read a book and use a torque wrench. I had an old johnson 125 that sunk on my boat docked behind the ship I worked on. I pulled the power head, set sail the next day, disassembled the powerhead and had a friend bring me $250 dollars worth of parts when we hit the next port. I put it back together, remounted the power head when we got back and it started right up. It ran for five years until I sold it. They do smoke at low rpm.

Whatever you do, don't buy an OMC ficht.

There is nothing you can fix on a computer controlled fuel injected engine

 

[jchaplain]

However everyone seems to be saying the same thing "the bigger the better".

Not me. I would go for a smaller engine unless I was in some big hurry to get places or I wanted to waterskii from it.
I don't know why so many feel they have to put on the biggest motor possible. Geez...what to sailboats do? ( and get there a lot cheaper.) A smaller engine is cheaper to buy and cheaper to operate.

 

[Donnie1442000]

Comparing a sail boat to a center console boat is like trying to comparing a tractor to a Ferrari. They are completely different creatures the sail boat has a displacement haul which has a top speed that is figured off of length and is designed to slice through the water. Once you reach the top speed it doesn’t matter how much horse power you putt on it all you are going to do is burn more fuel. On a planning hull if you are under powered you will never get it on a plain and you will burn more fuel then that sailboat and probably go slower. For a planning hull to be efficient you need to get that thing up and out of the water. I get better fuel economy at 25 MPH then I do at 15. At 15 MPH I’m getting maybe a mile to the gallon because I’m trying to push half of the ocean a head of me. You step it up to 25 MPH my boat comes up and out of the water I’m running on the back 1/3 of the hull and I go from 1 MPG to about 4 MPG. This is all calculated with GPS and fuel flow meters so the numbers are good. BY what I have read so far it looks like Nizzy is looking at a 2 stroke motor and if you put to much stress on a 2 stroke you can burn them up in a summer. 2-strokes are work horses but they need to be able to run which means getting them to run in the designed RPM range and not lugging it down to bad.


For the best information you could get on what to run check with the bayliner dealer. Walk right past all the salesmen and talk to the guys in back working on them.

 

[Pierre Siquet]

Better run a bigger engine at 4,500 than a smaller at 5,500 rpm for the same speed. Talking for my experience with 2strokes

 

[deeper thoughts]

Thanks for the responses everyone. The boat is rated for 125 hp max although I figured if I went with a smaller engine it would help save gas $$$$. However everyone seems to be saying the same thing "the bigger the better". Basically I just want to get on the water. I'll probably check out some local shops this weekend unless divinginn has a reasonable offer. Although its a bit of a drive. Anyway thanks again.

I have a 19ft key west with a 4 stroke suzuki 140 hp, its a great motor, quiet,great on gas, clean and plenty of power. If you have a place that works on suzukis I would highly recommend it