how thirsty is your motor?

1973Chieftain · Apr 12, 2012

Out of curiosity, how much gas does your motor use? My 40 hp uses right about 4 gallons/ hr running about pretty much full out and about 3.5 gal/ hr at cruising speeds.... how thirsty is yours?

sschefer · Apr 12, 2012

Re: how thirsty is your motor?

3.421052631578947 Just pulled it off my smart craft gauge. 60hp 4 stroke averged over 26 hours/84 miles. I was trolling most of the time but there were those 5 mile WOT runs back to the dock.

roscoe · Apr 13, 2012

Re: how thirsty is your motor?

All 2 cycle engines.

2002 50 Merc was bad, easily 5+ gph.
1995 Force 70 (single carb) was actually pretty good, 5.5 gph.
1984 Merc 75 4 cylinder is 6 gph.
1984 Merc 115 6 cylinder 10 gph

These are all running at about 4500-4800 rpm.
Motors are propped to turn 5400-5600.

Running at 3500-3800 rpm saves a a gallon per hour.

14 hours per gallon trolling with the 4 hp. (10 ounces per hour)

InMotion · Apr 13, 2012

Re: how thirsty is your motor?

Rough guide - HP / 10 = wot usage for 2 strokers. For cruising multiply wot figure x .6. Just a rough guide. I run a 90 HP Johnson --- 1988 vintage and it goes through roughly 3-4 gal at cruise --- but that is on a tiny ski boat that weights nothing.

dozerII · Apr 13, 2012

Re: how thirsty is your motor?

My Mercruiser 120 just sips the fuel even at Wot, but the V4 Evinrude can suck back a 5 gallon tank pulling a tube in 20 minutes.
Glen

CheapboatKev · Apr 13, 2012

Re: how thirsty is your motor?

dozerII said:
My Mercruiser 120 just sips the fuel even at Wot, but the V4 Evinrude can suck back a 5 gallon tank pulling a tube in 20 minutes.Glen

score one for I/O..lol

ezmobee · Apr 13, 2012

Re: how thirsty is your motor?

Even I will not argue the gas thriftiness of I/O's. Tim Fives and I traversed the entire length of Lake Raystown (I think like 26 miles or so) and back in his Islander with the 3.0 and I made him stop at the marina to top off his tank because I did not believe his fuel gauge. Thing only took like 15 gallons or something. He was like "now you wanna reimburse me to that expensive-a&% marina gas you just made me buy?"

CheapboatKev · Apr 13, 2012

Re: how thirsty is your motor?

ezmobee said:
Even I will not argue the gas thriftiness of I/O's. Tim Fives and I traversed the entire length of Lake Raystown (I think like 26 miles or so) and back in his Islander with the 3.0 and I made him stop at the marina to top off his tank because I did not believe his fuel gauge. Thing only took like 15 gallons or something. He was like "now you wanna reimburse me to that expensive-a&% marina gas you just made me buy?"

lol...nice

elkhunter338 · Apr 13, 2012

Re: how thirsty is your motor?

about 2-4 mpg depending on weather, 140 hp I/O merc.

BonairII · Apr 13, 2012

Re: how thirsty is your motor?

My '67 Johnson V-4 80hp(crossflow) inhaled gas like a pig. It would empty a 6 gallon tank in 30 mins if I was hard on the throttle.

My new(to me)'77 Evinrude 75hp sips gas in comparison. I ran the motor at WOT for 45 mins on my first shakedown run....and fuel consumption was nowhere near what the V-4 would have sucked down.

scubaspook · May 19, 2012

Re: how thirsty is your motor?

1985 17' Travelcraft walkthru hull I/O 3.0 about 7.5 mpg calculated thru gps
2003 22' Suntracker Regency pontoon I/O 3.0 about 3 mpg calculated on gps

just got the pontoon. Boy this pittifull. I was hoping with a 30 gallon tank I could travel farther than my other boat.

minuteman62-64 · May 19, 2012

Re: how thirsty is your motor?

30 HP Mariner, 1982, 2-stroke. About 2 GPH cruising at maybe 60% full throttle. Flat aft section precludes going much faster in most bay chop conditions.

1973Chieftain · May 19, 2012

Re: how thirsty is your motor?

Welcome aboard scuba!

starcrafter65 · May 20, 2012

Re: how thirsty is your motor?

I don't have exact numbers - but the 3.0 I/O in my 18' Holiday seems to run on some sort or perpetual motion device as its fuel consumption is easily less than half of my previous Mercury 800 2 cycle O/B in a 16' Nassau.

I wonder how the new 4 cycle O/B's are on fuel consumption - unfortunately they only cost one gazillion dollars:facepalm:.

I gotta say I tuned up the electrical in the 3.0 - new coil, new plugs, new points, gapped everything and what a difference - had the boat out yesterday and it ran quiet smooth and fast. I have a 19p and I think we are are mid thirties with that and pops with 6 lunkers weighing it down!

Mark_VTfisherman · May 20, 2012

Re: how thirsty is your motor?

Being a freshwater fisherman in a little 14' with a 40hp 2-stroke, GPH is not really something I calculate or need. MPG, on the other hand, is probably really around 5mpg at about 3/4+ WOT. WOT it goes way down to maybe 3 mpg-ish. Surprisingly similar MPG trolling... While trolling it would probably be handy to calculate GPH but honestly - my maps and GPS all show mileage. It is just simpler for me to figure mileage for my situation.

Basically I "calculate" probably 3mpg when I am out to assure I have sufficient fuel for the return flight. And I keep 2.5 gallon can as a safety reserve. In reality if the map says I am headed somewhere 6 miles away and the water is not too rough to cruise at 22mph (seems to be best compromise of speed and MPG) I figure a gallon-and-a-half one way (4mpg). If I have to run in waves, especially into them, I figure on about 3mpg as I will not be planing but thumping along at 8-9mph with the bow high.

Some of those i/o numbers are enviable.

starcrafter65 · May 20, 2012

Re: how thirsty is your motor?

Maybe this should be answered like this:

My Boat is so thirsty that ......"having a 3.0 I/O is so effecient - I often have to siphon fuel OUT during use to prevent spilling"

1973Chieftain · May 20, 2012

Re: how thirsty is your motor?

Wow, that 3.0 sounds efficient! My Merc 500 goes through almost 4 gallons in an hour. I've never figured out the mph, just how much I burn in an hour of fooling around.

djpeters · May 20, 2012

Re: how thirsty is your motor?

My '85 140 Evinrude (Looper), burns 6 gallons an hour at 25mph cruise, 4800 rpm's. It figured out to 3.3mpg.

FishNmemories · May 20, 2012

Re: how thirsty is your motor?

our '96 60 hp Yammie will burn 5-6 gals for 6 hour day of fishing, which includes 9-10 mile return trip at 4000 rpm...rarely wot

64osby · May 21, 2012

Re: how thirsty is your motor?

1973Chieftain said:
Wow, that 3.0 sounds efficient! My Merc 500 goes through almost 4 gallons in an hour. I've never figured out the mph, just how much I burn in an hour of fooling around.

Max speed is 30, most likely avg speed 20 to 25 divide by 4 if avg 24mph /4gal = 6 mpg.

I ran that motor with the 6 gal and a 2 gal back up tank. Only had to change to the back up twice. I also didn't go wot all the time.

how thirsty is your motor?

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