78 Johnson V4 85 HP Fule consumption question.

[lilroud]

I got a older V4 Johnson on a 1991 Stratos 254 15.5 foot V hull. I think the boat maybe weighs 800-900 lbs dry . Its my first boat so I not sure if im doing good or not with gas consumption. But I was out yesterday topped the tank off before i went out. I was at WOT the whole time and went a lil over 12 miles before I had a half tank to make it back... when I did make it back there was maybe a gallon of fuel left. This was on a clear day and the water was calm. Is that bout right for this motor? I rebuilt both carbs and changed all the plugs. Thanks




Edit: So im assuming I can go bout 25 miles???
Edit #2: Im assumming the prob pitch i have on it will help... but Im not sure what kind is on it.. any way to tell?

 

[Bill3434]

Re: 78 Johnson V4 85 HP Fule consumption question.

Has a rule of thumb 10% of your horsepower per hour. In your case it should be about 8.5 gallons per hour.

 

[lilroud]

Re: 78 Johnson V4 85 HP Fule consumption question.

Well I guess im doing good? Cause I only have a 6 gallon tank

 

[lilroud]

Re: 78 Johnson V4 85 HP Fule consumption question.

And of course Im able to put a lil more then 6 gallons in it....

 

[Bill3434]

Re: 78 Johnson V4 85 HP Fule consumption question.

Might want to get a bigger tank or a second tank. I got two tanks for my 70hp. All day on the lake I come in with a gallon of fuel left. That's for fishing, no skiing or tubing.

 

[lilroud]

Re: 78 Johnson V4 85 HP Fule consumption question.

I just looked at my log, in 22 minutes a was near a lil over half tank while under WOT. 6 gallon tank... so i used 3 gallons roughly... i turned around took another 20 minutes at wot to get back to marina with a gallon +/- to spare. so another 20 minutes would be right in the ball park of your rule of thumb. Thanks for your response

 

[lilroud]

Re: 78 Johnson V4 85 HP Fule consumption question.

Yeah. I was looking for a used plastic 12 gallon on Craigslist. the guy I bought it from said i may want to get a bigger tank as well when I was buying it.

 

[Bill3434]

Re: 78 Johnson V4 85 HP Fule consumption question.

It's not my rule of thumb, just a bit of info I came across here on iboats. Seems to work for planning purposes actual fuel consumption may vary. LOL

 

[GeneH]

Re: 78 Johnson V4 85 HP Fule consumption question.

It's not my rule of thumb, just a bit of info I came across here on iboats. Seems to work for planning purposes actual fuel consumption may vary. LOL

I often use the regular 5 gallon gas tanks to carry spare fuel. You can take your oil separately and mix it as needed then transfer to your outboard fuel tank. I wouldn't go out with only 6 gallons on an 85 unless I was only going to be gone 30 minutes total!

 

[Bill3434]

Re: 78 Johnson V4 85 HP Fule consumption question.

I often use the regular 5 gallon gas tanks to carry spare fuel. You can take your oil separately and mix it as needed then transfer to your outboard fuel tank. I wouldn't go out with only 6 gallons on an 85 unless I was only going to be gone 30 minutes total!

I only got so much space in a 16ft trihull. Besides the largest lake in Kansas ain't really that big. I change my 1st tank out when it gets down to the last 1.5 gals. and call that as my emergency reserve. I have used it a couple of times but I was trolling back to the dock with the wind to my back. Worked out great except the fish didn't want to bite my hooks:blue: