yamaha 350 fuel economy

[smess]

I am building a boat with a pair of 350's, does anyone have any info on hiw thirsty of a motor it is?

[propbender24]

The reports I have seen show 13-15 gph a piece @ 4000 rpms, and 33-35 gph a piece @ wot,
I beleive 89 octane is required

What boat are you building?

[smess]

do you know how that compares to a merc verado 300?

[propbender24]

The verado 300 burns 9-12 gph @ 4000 rpm, and 28-30 gph @ wot
You can run 87 or 91 octane, and the performance change is marginal

The 300 opti burns 9-11 gph @ 4000 rpm, and 24-25.5 gph @ wot
91 octane is required

[Whaler27]

Can't validly compare motors on an RPM to RPM basis. The F350s don't have to spin as fast to push a boat the same speed as a Verado 300. For example, triple F350s get the same fuel economy on the Everglades 350 CC as triple Verado 300s at 36 and 48 MPH according to each of the manufacturer's test reports but the F350s are turning 500 RPM slower and are pushing around more weight.

[propbender24]

You are right that you can't compare the rpms unless you are turning the same pitch wheels and the same gear ratio. However, the most important fuel burn rates to me are idle, cruise, and wot fuel burn. I generally cruise my outboards at 4000 rpm unless I am in a hurry. I think the original poster is trying to get an idea of what it is gonna cost him to run whatever boat he buys.

[Gillagorilla]

We have a pair on the back of a 08 Robalo 305 at 4000rpm cruise it uses 26-27gph at around 35mph with a good load.

I can't verify yamahas performance #'s at WOT because 67gph gets expensive very quickly.

[TwentyFourSeven]

Whaler27 - 6/28/2008 6:11 PM

, triple F350s get the same fuel economy on the Everglades 350 CC as triple Verado 300s at 36 and 48 MPH .

I seriously doubt that. Even trip 300 verados get slightly better (Almost identical) fuel economy than twin 350 Yam's.

[Whaler27]

TwentyFourSeven - 6/29/2008 9:52 AM

I seriously doubt that. Even trip 300 verados get slightly better (Almost identical) fuel economy than twin 350 Yam's.

Here you go:

Everglades 350, triple F350s, 250 gallons of fuel

RPM MPH GPH MPG
1000 7.5 4.7 1.60
1500 9.6 8.4 1.14
2000 12.1 15.0 0.81
2500 21.7 18.9 1.15
3000 30.2 26.3 1.15
3500 36.5 32.5 1.12
4000 41.6 42.0 0.99
4500 48.7 55.5 0.88
5000 54.3 70.1 0.78
5500 59.8 91.4 0.65
6000 63.1 102.3 0.62

Data from http://www.yamaha-motor.com/assets/p...c-tri-f350.pdf


v.

Everglades 350, triple Verado 300s, 191 gallons of fuel.

RPM Range Speed (MPH) Fuel (GPH) Fuel (MPG)
1000 5.5 3.0 1.8
2000 9.8 9.3 1.1
3000 23.4 17.4 1.3
4000 35.7 33.3 1.1
5000 48.1 55.2 0.9
6150 60.2 89.4 0.7

Data from http://www.mercurymarine.com/look_de...sixCyl200300=4

[propbender24]

Comparing the #'s above I would go with the Verados on that boat. They burn less fuel at wot, less fuel at idle, and the same fuel at cruise. They are also gonna burn less fuel in the ocean at cruise b/c with the Yam's you are gonna have to run the tabs lower with an extra 600 lbs on the transom. Tabs will eat up some fuel.

I am an opti guy, and I bet a set of trip 300 opti's would be quite a bit better than both of the other power options.

That hull is begging for the 350 verados

[Whaler27]

propbender24 - 6/29/2008 11:24 PM

They burn less fuel at wot, less fuel at idle, and the same fuel at cruise.

I don't see it. The Verados burn less fuel at WOT because the boat is going slower. If you pull the throttles back on the F350s to 5500 RPM, they are burning fuel at the same rate as the Verados going the same speed as the Verados at WOT. At 1000 RPM, the F350s are using more fuel but also pushing the boat faster. Keep in mind that the F350 boat in this comparison is hauling around an extra 60 gallons of fuel. Burn off that 60 gallons and the fuel economy numbers will improve from what was reported

Basically, these two reports show the F350s are about dead even with the Verado 300s in the fuel consumption department. Based on these I would go with the F350s because they turn can slower to get the same speed but only if the handling of the boat isn't negatively effected by the their extra weight. There is enough of a weight difference hanging on the transom that boats with both types of motors should be run to see how they handle.

[TwentyFourSeven]

I dont believe anything I read on a manufactures site period. Its all stretched truth. The f350 are gas pigs. Not to mention why would anyone buy a boat with an unifficient hull this day and age with fuel prices as high as they are. I have a 36' Yellowfin w/trip 300 Verados. Of the top of my head here are a couple numbers.
250 gallons of fuel, 80 gallons of water, 2 people and 100 lbs of ice.
at 41 mph I burn 26 gph. = 1.6mpg
at 44 mph I burn 31 gph. = 1.4mpg
at 50 mph I burn 44 gph. = 1.2mpg
Wot 65 mph burn 89 gph. = .74mpg
At the moment the only boats I would even consider for fuel efficiency would be. Yellowfin, Fountain or Incinvible.

[smess]

I believe the yamahas weigh 123 pounds a piece more than the 300 verado.

[propbender24]

I could be wrong, but I thought the v-rods were about 650 lbs. wet, and the yams are about 840 lbs. wet.

I am sure the performance reports aren't dead on accurate, but the Yam boat must be spinning some high pitch props to be idling that fast, or maybe they are running in a 2 kt. current.

The extra 2.9 mph on the top end is not worth the extra 13 gph imho. But, that may be more of a result of the hull design.
Once again, I am basing my opinion on how I run my boat. 90% of my hours are at idle, efficient cruise, and wot

[qqqa]

single 40 suzuki, 4 hours of skurfing/tubing costs me $25 thats like 5 gals, 1.25 GalsPerHour

wootwoot love my small boat

[flats392]

Slap on a pair of Suzuki 300's and be done with it.....

They are the lightest and most economical big hp 4stroke outboard made today.

[ken2]

Here is a little info for you.

31 Capehorn 2008, Twin F350 Yamaha's

Test Conditions.
3 guys
Running into a 10mph wind.
Fuel load of fuel, 290 gal
Tournament load of Fishing gear

Yamaha 23 pitch props. (These props had extra cup added, which reportedly ran a little better then stock)

RPM MPH GPH total
3500 38 24
4500 48.4 39
5600 WOT 61.1 64.5


Powertech 23 pitch OFS 4 blade props.

RPM MPH GPH total
3500 40.8 25
4500 50 42
5400 WOT 61.7 61

[Gulf Cart]

I have twin 350's on my GW 33 Express. 250 hrs - been flawless...

CLose to 16k loaded. Just went 600 miles to the Keys and back.

Cruise 3800 to 3900 RPMs..... 1.1-2 mpg @ 30-31 MPH

[crackerasscracker]

The F-350s are V8 5.3 liters and the Verados are V6 2.6 liters. Take that however you want to take it.

[propbender24]

CAC, The v-rods are an inline 6 cylinder