95" Merc 7.4..Gas hog?

[hill392]

Doing some boat shopping and ran across nice boat with a 1995 Merc 7.4, 454 with alpha outdrive. I know ..if I have to ask then I probably can't afford it..but whats the fuel consumption like with these monsters? The boat is a 23ft Larson BR.

 

[Bondo]

Re: 95" Merc 7.4..Gas hog?

Doing some boat shopping and ran across nice boat with a 1995 Merc 7.4, 454 with alpha outdrive. I know ..if I have to ask then I probably can't afford it..but whats the fuel consumption like with these monsters? The boat is a 23ft Larson BR.

Ayuh,... Sounds like a Cobb Job,...
The 454 only came with the Alpha for a couple of years,...
'n those years were well before 1995...

Yes, it's a Big Block,...
But,.. Fuel mileage is completely controlled by the operator's right hand...

 

[NHGuy]

Re: 95" Merc 7.4..Gas hog?

That's the right amount of motor to move a 23 footer. A 5.7 is the next size down and it would have to be on boil most of the time.
Fuel usage is a function of many things. There's engine condition, boat weight, hull type, weight carried, state of tune up and bottom condition. Boats use so much fuel that it's imperative to keep em well tuned to help control fuel use.
Carbureted engines are simpler to repair. They use more fuel than injected motors.
Fuel injection systems are more powerful and efficient. They are electronically controlled and require valuable diagnostics gear to work on certain issues with them. They do use less fuel unless you are a cowboy with the throttle.

The thing that really controls fuel use is your throttle hand. If you get the boat just up on a plane and trim it well you can somewhat mitigate the cost of gas. But that boat will ride nicely and if it were me I'd want to go for long rides.
Each boat is different, but with that boat I'd say you could spend a hundred on gas in an hour or three if you keep in the throttle.
If you are like me you'll be smiling the whole time though!

 

[45Auto]

Re: 95" Merc 7.4..Gas hog?

Best thing you can do is go to Boattest.com and look at the real test data for similar boats.

What you'll find is that no matter what engine is in it, at best cruise a 17'-18' foot boat gets about 5 MPG , a 19'-21' gets about 4, a 22'-23' gets about 3. A bigger engine will often actually give you better fuel economy as well as the option to really waste gas if you decide you need to plane quicker or go faster. Whether you use it or not is up to you.

You can see from the test data on the Stingray website that all the 22'-23' Larson's get just over 3 MPG, no matter whether they have a 5.0L or 5.7L motor.

They didn't have a Larson with a 7.4L, but these are all about the same size with a 7.4L or an 8.1L motor.

You can see how much difference the engine size makes to the fuel economy. Notice how EVERY 22'-23' boat on both pics gets just over 3 MPG.

 

[hill392]

Re: 95" Merc 7.4..Gas hog?

Thanks for all the info. Seems like the boat may be worth taking a look at. I'm looking for a boat to be able to haul more people. So mabey bigger motor is what I should be looking for. 3mpg is what my old ranger used to get..if that. Heres the link to the craigslist add http://stlouis.craigslist.org/boa/2493101546.html

 

[Pete104]

Re: 95" Merc 7.4..Gas hog?

Well, the post itself says "Bravo I". So you went en got Bond-o all tightened up over nothing. But relaxed by telling you, "it's all in your right hand"! They are not very forgiving (the 7.4) on gas but it's alot of motor! The trim tabs will make a big difference on carrying big loads.

 

[hill392]

Re: 95" Merc 7.4..Gas hog?

Dohh!! Yeah sorry Bond-o..I thought I corrected that.I've looked at to many boats over the last week. Yeah a lot of motor for sure. Interesting boat. I'm sure it needs the motor with a seating capacity of 16.

 

[HT32BSX115]

Re: 95" Merc 7.4..Gas hog?

Doing some boat shopping and ran across nice boat with a 1995 Merc 7.4, 454 with alpha outdrive. I know ..if I have to ask then I probably can't afford it..but whats the fuel consumption like with these monsters? The boat is a 23ft Larson BR.

Howdy,

Mine uses 10 gallons per hour at 3000 RPM (at about 30mph) using the following fuel flow gage sold right here on iboats!!

http://www.iboats.com/Lowrance-LMF-...6136179--**********.444603245--view_id.361223

That's mi/gallons now but a simple push of the button gives you gallons per hour.

It IS really just a function of how far you push the throttle. It wouldn't matter (a LOT) if you used a 454 or a 350. The 350 would just require a little more "push" on the throttle but , it would burn approx the same amount of fuel to push the boat the same speed... (just simple physics) you would just have more available power with a 454.......(AND of course ......like ME......you would use it too making you use more fuel )


I wouldn't have a boat that big with anything smaller than a 454 either......


Cheers,


Rick

 

[hill392]

Re: 95" Merc 7.4..Gas hog?

Thanks for posting that..I like that fuel meter..might look at boat tomorrow....Price seems a little high for a 95..

 

[HT32BSX115]

Re: 95" Merc 7.4..Gas hog?

Thanks for posting that..I like that fuel meter..might look at boat tomorrow....Price seems a little high for a 95..

St Louis does get (hard) freezing weather every winter. Ensure that the engine is not damaged from improper winterization!

If you're not well versed in checking that and you decide you want the boat, you should have a reputable dealer carefully inspect it for you.


Cheers,


Rick