Fuel consumption

D

diggindan

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Jun 15, 2009
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Junction City
Hey all,
We bought a new for us boat awhile back and love it. One concern is trusting the gas gauge.
90 HP Merc 4 stroke. 27 gallon tank. I filled it at least 4 all day outings ago and the gauge still reads 3/4 full. We do mostly putt around. I opened it up on Siltcoos this afternoon for about 5 minutes. 33 mph! Fast enough for this old guy!
Anyway, should I carry a gas can with me? Do these new motors get that kind of mileage? I'm used to the old 2 strokes burning 10 gallons a day.
Thanks for any input.
Didn't bring anything home today but had a great outing anyway.
Cheers, Dan
 
S

SNDSLGR

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Mar 21, 2009
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236
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Pacific NW
If your gas cap is in a place hovering over the tank then you can "stick it". Get a wooden dowl or similar and poke it to the bottom of the tank, the wet fuel will show you whats left.

Otherwise I would put a small can on board until you know for sure. No way you have used less than 10 gallons in 4 days I would say. If I had to guess it would be about 4-5 gallons per hour of med-hi running time.
 
Irishrover

Irishrover

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Hey all,
We bought a new for us boat awhile back and love it. One concern is trusting the gas gauge.
90 HP Merc 4 stroke. 27 gallon tank. I filled it at least 4 all day outings ago and the gauge still reads 3/4 full. We do mostly putt around. I opened it up on Siltcoos this afternoon for about 5 minutes. 33 mph! Fast enough for this old guy!
Anyway, should I carry a gas can with me? Do these new motors get that kind of mileage? I'm used to the old 2 strokes burning 10 gallons a day.
Thanks for any input.
Didn't bring anything home today but had a great outing anyway.
Cheers, Dan

What size and type of boat is that 90hrs motor pushing? It will make a difference on fuel consumption. The four strokes do get better fuel consumption. I had Johnson twin 110 2 strokes they were not fuel efficient at all. A couple of years ago I remotored with Mercury twin 115hrs 4 strokes. They are much better on the fule useage. I use the boat off shore out of Newport mostly. I never trust the gas gauage. I top off the tank when I return from a trip then I have a full tank for the next trip. Depending on the lenght of the trip I'll use between 10 to 12 gallons. I'm more than happy with that level of fule consumption. If you are going slow on a lake chance are you are not burning much fuel.

Again I never trust the gauage. I will list the boat when filling it to make sure there are no air pockets in the tank. Hope this helps.;)
 
D

diggindan

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Jun 15, 2009
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119
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Junction City
Thanks for the ideas and the Mercury link. The boat is an 18' Jetcraft and we do just putt around mostly. We don't have a kicker yet so we troll with the 90 also.We use 2 sea anchors to slow it down some.
A buddy recommended filling the tank to see how much I've used. DOH!! He's a smart feller.:rolleyes:
Do you add anything to your gas this time of year?
 
Irishrover

Irishrover

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Sta-Bil gas treatment

Sta-Bil gas treatment

When I bring the boat home for the winter I usually top off the tank and add a product called Sta-Bil Cabela's -- STA-BIL Fuel Stabilizer

You can pick it up at most auto parts stores. I fill the tank to leave less room for condensation then add the fuel treatment. It has worked for me so far.
 
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joesnuffy

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Oct 1, 2008
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Baker City, Oregon
YOu should actually run teh engine after you put the fuel stabilizer in the gas. This way the fuel in your carbs and lines is better protected too.
 
E

ecarpet1

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Nov 14, 2009
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I was going to say after a day try filling it up and see how much you use on most days. The new gas cans that automatically shut off when the gas gets tot the top of the tank are really handy.
 
D

diggindan

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Jun 15, 2009
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Junction City
Kinda slow posting this, it's that memory thing again.
After 2 more 4-5 hour trolling trips I topped off my tank before going to the Alsea for crab. The pump shut off at 15 gallons. At least 30 hours of running around, not much high speed.We idle around mostly.
After owning many 2-stroke out boards I'll never go back.
Very happy with my Merc 90 EFI.:D
 
Irishrover

Irishrover

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Diggindan, that's great. That's the rate I would burn .5gph at an idle or slowest troll.
 
D

diggindan

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Junction City
Yeah, I'm really happy with this motor, 4-stroke EFI is the way to go.:dance:
I don't catch any more fish but my outings are more pleasant.
Cheers,Dan
 
S

stream2.5

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Jan 26, 2010
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NE P-Town
someone is idling a lot... that motor idles at .4 GPH and at WOT will burn approx 7.8-8.2 GPH.. and 27 gallons of fuel at 33 mph gives you almost 4 HOURS of WOT throttle time... id trust the gauge more than you would think... i dont trust gauges i didn't install... because a lot of tanks are very narrow in thickness there fore the gauges take a long time to swing and are not very accurate below 1/4 tank..
 
D

diggindan

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Junction City
Yeah, we usually start trolling as soon as we leave the dock. I open it up a bit when crabbing but not much. I don't appreciate boat wakes when I'm pulling pots so I try to be considerate to other folks. I'm never in much of a hurry anyway.;)
I'm looking for a kicker now to get that slow troll handled and for backup just in case. Hoping to find a gently used EFI 4-stroke 10-15 HP.
Cheers, Dan
 
S

stream2.5

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being you already have a black painted mercury v6 cowl disguised yamaha id look at the T8 one of the best kickers out there today
 
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