Realistic usable fuel range 1990 F3

[abear]

I am trying very hard to search first before posting, I want to be a responsible member of the group. That said I have found the spec sheet on the 1990 F3 and it appears I have 27ish gallons of fuel . I will be using my skier on a river, not a lake. In Florida we have a lot of manatee zones and no wake zones on the rivers. As I understand it, on a 350ci inboard I can burn up to 18 GPH at WOT. This is a good outline, but there is a lot of room for error. From my launch it is roughly 90 miles round trip to our furthest destination (Salt Springs). In order to get here from our marina we have to boat through a VERY long idle zone at Hontoon Island/Blue Springs State Park, roughly 45 minutes and 5 miles, based on experience and google maps.

I tried to find moorage at Pier 44 marina, but the person on the phone said they are not taking new dry rack customers at this time......sucks for me as this would cut 14 miles, and all of the manatee zone out of my projected boating area.

My calculations tell me I either have to refuel every trip mid-way, or be at the ragged edge of the capacity, leaving no extra fuel for towing skiers.

As some of you know, I am putting together a project so I have some latitude in options. Could I install a slightly larger tank in the stock location? Since I will be skiing, and will have little use for ballast bags, could I put a second smaller tank up-front under the closed bow?

As I said, I am trying to search, but there will be a few questions over the next month.

Steve

[justgary]

You won't burn very much fuel at idle, and you will get much better mileage if you don't run WOT. Generally, you will get your best mileage if you run at your engine's maximum torque RPM, so maybe 3500 or so.

Rather than modify the boat, I would carry extra cans under the bow. Even better, can you have some of your crew meet you there with fuel cans in their car?

Finally, it would probably be worth the cost of a trailer to get you close to your chosen trip, especially if you plan to do the 90 miler very often.

[electricjohn]

No waterfront gas docks? I normally get 8 hrs out of 35 gallons of fuel. Just cruising would be a lot higher, but I never just cruised. Best miles per gallon range on our boats is at 3200 rpm. Going above that causes a drop off that is exponential.

Edited May 30, 2015 by electricjohn