Got Gas?

[Kmestep]

Afternoon All,

I'm about to start my first project boat so I'm looking forward to using this forum and all the resources it has to offer. My first question is one that I've been trying to figure out for a while.

I have a late 70s 115HP Evinrude (sorry, unsure of exact year) that guzzles gas. I'm running this fairly strong motor on a 15ft Tri-Hull so it's not having to work that hard.

I run through an average of 12 gallons of gas every 45 minutes or so and I'm running around 20mph. I have to believe that the engine is supposed to be more economical than this.

Any help you have would be great and thanks for reading!

 

[HighTrim]

Re: Got Gas?

IN general, that outboard will burn roughly 11.5 gallons an hour at WOT. Cruising will be less. This figure will vary 10 to 20 percent.

 

[Dhadley]

Re: Got Gas?

Seems a bit excessive but you didn't mention the set up. If your top rpm is 3500 and the speed is 20, something's very wrong. If the top rpm is 6000 with a top speed of 20, something's very wrong.

What's your top rpm with an average load and the pitch of the prop. Verifying the top speed with a GPS would help. With that we can figure your percentage of slip. It'd help to know the model number too.

 

[ezeke]

Re: Got Gas?

Just for comparison, it would not hurt to do a trial run without the whale tail. Also be sure that the A/V plate is at most no lower than the bottom of the boat. Also, when on plane, make sure that your A/V plate is parallel to the water.

 

[Kmestep]

Re: Got Gas?

Well I don't have a Tach so that'll be on my list of things to add. The whale's tail is good idea...i'll give it a shot. I can also adjust the plate so that the motor is where it needs to be. I'll let you know the outcome. Thanks guys!

 

[tashasdaddy]

Re: Got Gas?

if you can get a timing light with the tach feature it will work, with out having to buy a tach.

have you check the compression and spark on all 4 cylinders? if not do it.

 

[Kmestep]

Re: Got Gas?

if you can get a timing light with the tach feature it will work, with out having to buy a tach.

have you check the compression and spark on all 4 cylinders? if not do it.

Compression is good on all four and I just replaced the plugs and wires.

 

[SouthernAppal]

Re: Got Gas?

Crikey!! I just bought a very similar boat and motor--79 Crestliner 15 ft Muskie with an 84 Evinrude 115 hp VRO V4. Haven't put it on the water yet, as seller kept battery and gas tanks.

Please post what you learn about your gas consumption.