Does anyone know the GPH for a yamaha 6hp (4stroke)

tommays · Jul 23, 2012

About 1/2 gallon BUT its hard to say as most of the time full power is not required

Things like what prop you use also have a big effect on it

Rick Webb · Jul 23, 2012

If it Helps

My two stroke 6hp Mercury burns about a gallon an hour at WOT.

Attwood makes a six gallon tank that fits in the lockers on a 23.5. If I fill up two I am good for a 70 mile trip to Shell Island and back.

Benny17441 · Jul 23, 2012

I would use a conservative 3/4 gallons per hour for trip planning purposes. Do not forget that not all the fuel in the tank is usable and a 15% to 20% reserve of usable fuel is recommended. I usually estimate range based on a speed of 4.5 knots but once in the water will recompute range according to conditions.

rpell1@msn.com · Jul 23, 2012

I had both a 9.9hp and 8hp Yamaha 4-stroke, High Thrust outboard. Both averaged
3 quarts per hour over the course of a season....roughly 7 months.

kloudie1 · Jul 23, 2012

Had a 7.5 Honda on a Spirit 23.. about half a gallon/hour

Charlie Jones s/v Tehani · Jul 23, 2012

2 1/2 years experience with a Yamaha 8 HP 4 stroke, on a 25 foot, loaded 7600 pound displacement boat. 7000 miles total, not all powering of course. Standard prop.

At JUST under the start setting on the handle, I got 7 1/2 to 8 hours from a 6 gallon tank, regularly. Worked out to just about 15 MPG.

NEVER ran it over half throttle, which gave us a TAD over hull speed- squatted the stern at anything over that

The 6 HP from then is a two cylinder detuned 8, so you should do about the same. The newer 6 HP's are single cylinders, so not as smooth.

I just bought a Yamaha 4 HP (different boat) and when I ran the internal 1.5 liter tank dry, at just under "start", it took almost 3 hours

I think you can safely figure 1/2 gallon/hour.

Oh, and I figure average speed at around 4.5 mph, day in and day out

FastOlson · Jul 23, 2012

I was using a 10 hp HiThrust Yamaha OB (25" leg) on my 26' 4000# sloop for almost a decade. Cruised under power all (windless...) day at 5.9 kt.
One Half gallon per hour.

When we first bought that boat it had a Honda 10 hp that also burned a half gallon per hour.
No guess on that, either -- I once did a windless trip out the Straits and all the way down the WA coast. 46 hours under power. Half gallon per.

Thrifty engines..... and powerful, too...
Hard to imagine the 6 hp Yamaha doing worse.

higgs · Jul 23, 2012

It will depend on many factors including the weight, wetted surface, etc of your boat. Only way to know for sure is sea trials.

Tom · Jul 23, 2012

how about topping off your gas tank & motoring for 30 minutes (X 2) or 15 minutes (X4) and then topping off the tank again measuring the gas you put in (X 2 or 4) then you would know.
just a thought.

tom

s/v GAIA

monkeybars · Jul 24, 2012

tohatsu has a chart/page to figure this on their website,both yamaha and merc are just repainted tohatsu's.

Charlie Jones s/v Tehani · Jul 24, 2012

monkeybars said:
tohatsu has a chart/page to figure this on their website,both yamaha and merc are just repainted tohatsu's.

Merc, yes- Yamaha no- different company totally. And completely different engines.

anchorclanker · Jul 24, 2012

While there are often major differences from one make to another, you can compare fuel burn rates between comparable engines. A 6 HP 2 cylinder 4 stroke outboard from XYZ isnt going to burn an appreciable amount more, or less, than any other 6 HP 2 cylinder 4 stroke outboard. They should all be within 10% of each other, as a group.

For planning purposes it sounds like you can safely figure a gallon per hour. If you give yourself a 2 hour reserve you should be okay. Nothing worse than running out of fuel 3/4 of the way.

rpell1@msn.com · Jul 25, 2012

...Totally agree that Yamaha is a completely different animal. I've gone through Mercs and Tohatsus, dissappointed with their reliabiliity. But, both of my old Yamaha 4 strokes are still cranking on different owner's boats.....with never a problem.

Charlie Jones s/v Tehani · Jul 25, 2012

When I left the Keys a year or so ago, I started noting outboard brands on boats we passed.

All through the Bahamas, and up the east coast, on up into the Chesapeake, then back around to the GOM. Yamaha OWNS the outboard market, something like 4 or 5 to one.

A far distant second was Mercury , then all other brands WAY back in third.

Must be doing something right-grin

anchorclanker · Jul 25, 2012

TSBB 2 said:
Yamaha OWNS the outboard market, something like 4 or 5 to one.

A far distant second was Mercury , then all other brands WAY back in third.

Must be doing something right-grin

Has more to do with dealer networks and promotion, there is nothing at all special about a Yamaha over a Mercury or anything else. If there is greater dealer support and promotion for a particular brand, in a particular region, thats the brand people are going move towards. Market saturation.

Dont forget dumping practices supported by Japanese government subsidies too, which was proven by the DOC some years back. Offering a similar rated HP motor for less than the competition is going to make an impact in sales, especially in a region where poverty is rampant.

monkeybars · Jul 25, 2012

WORLDWIDE tohatsu-nissan has the market pretty much cornered,and that doesnt include all the motors it makes for merc,yamaha,and others.

Charlie Jones s/v Tehani · Jul 25, 2012

As I said- they must be doing doing something right. But in some 7000 miles of travel along the US coast, and through the Bahamas, over a 2 year period, I saw Yamahas on the back of boats 4 or 5 to one over ANY other brand. Personally, I have two, which is why I began to pay attention.

Also noticed quite a few on the back of Pangas during a delivery trip to Isla Mujeres, via Progreso, Yucatan, last year

Again, must be doing something right, and if it's market saturation, it's pretty wide spread.

Maybe it's just a good engine?

Charlie Jones s/v Tehani · Jul 25, 2012

Oh and by the way- Yamaha outboards are built by Yamaha Motors. They just celebrated the 50th anniversary of production. Yamaha outboards are produced at five factories in Japan, France and Brazil

Tohatsu builds Nissans, Mercurys ( smaller ones) and of course Tohatsus...All Tohatsu outboards are produced in their state-of-the-art factory located in Komagane, Japan.

Don't believe it? Do the research

JerryA · Jul 26, 2012

I use a little more than a gallon to go 18 miles with a Yamaha f8 on my Precision 23. That's at 4.5 to 5mph.