Fuel usage in 1970 Evinrude 25HP

[ncpi]

Now that I have it running well, what should I expect for fuel usage in my 1970 vintage Evinrude 25HP at cruise speed? My tank is only 6 Gal...want to be prepared. I am running 50:1.

Thanks, Bill

 

[rockyrude]

Re: Fuel usage in 1970 Evinrude 25HP

The accepted rule of thumb is 10% of hp = gph at WOT, or 2.5 gph at WOT. At cruise, that number will probably go down to around 1.5-2 gph depending on load.

 

[ncpi]

Re: Fuel usage in 1970 Evinrude 25HP

Thanks! More than I hoped as I have to run at 85% or so to keep on plane with my older style bass boat. Near 2.5gph is probably what I saw yesterday as I used more fuel than I expected but didn't have it measured nor did I time my running time. I guess I need to plan for 2.5gph and make some measurements....and start looking for a 12 Gal tank that will fit

 

[Georgesalmon]

Re: Fuel usage in 1970 Evinrude 25HP

Or,since you are close to underpowered get another 6gal. You can then put the extra weight where needed. And you'll know when 1/2 your fuel is gone without looking.

 

[kfa4303]

Re: Fuel usage in 1970 Evinrude 25HP

+1. I like the idea of 2, 6 gallon tanks as well. You can have one, or both at a time and move them around as needed. Plus, if one batch is bad, springs a leak or gets contaminated in some way, you always have a back up. If it makes you feel better, I get about the same fuel useage (10% of hp) out of my 20 hp. @ about 2.0 gph on my 14' tinny. It doesn't sound great at first, but I can still run around all day, from idle to WOT, and still have more than 1/2 of a 6 gallon tank left, which works out to about $10-$15 in gas per trip. Not great, but not so bad either and you get all of the old school 2-stroke torque for free

 

[ncpi]

Re: Fuel usage in 1970 Evinrude 25HP

The extra 6 Gal is not a bad idea but I was trying to conserve space. Vertical space is free if I can find a 12 Gal with a similar footprint to my current 6 Gal. A second tank would definitely be in the way but better than not having the extra fuel.

Thanks for confirming your fuel consumption too. Nice to know mine isn't way off.