Inboard gas tank feeding outboard motor?

Apr 23, 2014
54
Irwin 28 Long Island
I'm installing a new 9.9hp outboard motor on my sailboat since the old Atomic 4 has seen better days. In figuring out where I would put the standard portable gas tank that comes with the outboard, an idea hit me. Could I use the original below deck gas tank that fed the inboard for the outboard? Run a new gas line aft to the outboard with the squeeze hand pump in the middle. Would it work? or am I crazy? I would get ridiculous motor range if I could figure it out.
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
just make very sure you put a filter between the new line and the old tank preferably one you can service with a cartridge/element
 
Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
just make very sure you put a filter between the new line and the old tank preferably one you can service with a cartridge/element
And a blower. I have my boat set up like this with a 17 gallon tank below the cockpit. But you need a blower that is spark proof and you need to run the blower about a minute or so before you hit the electric start button. If any gas fumes leak into a confined space, you could have a real (but brief) problem when you hit the start button.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Maybe it won't work. Outboard engine fuel pumps may not have enough suction to overcome the length and rise of the fuel line.
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
Suggest going with the thinner ID hose (3/8"?) so the fuel pump suction has enough pull. (or step it down, depending on length.)

The larger ID hose might not get enough suction, and the 10hp won't need that much fuel.

+ watch for air leaks. those glass 'puralator' type filters are a common source of air leaks.

WOT was never a problem, but motoring in the channel was (with the larger ID hose) ie., starvation... but my experience was with 2 strokes (9.9/15hp), so your YMMV..

something like this would be good..

http://www.amazon.com/Racor-320R-Rac-Series-Filter-Outboard/dp/B0000AXT9M
 
Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
Yep, I too have 2x30 gal tanks in my lazarette feeding my Yami 9.9. Fuel filter is at the highest point above the tanks and feeds the outboard with 3/8" hose. One thing I was taught was to keep the suction bulb vertical with the anti-siphon on the bottom. Not sure why but it has not done any harm so that is what I do. No problem with the outboard getting enough gas.
 
Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
Suggest going with the thinner ID hose (3/8"?) ...(snip)
When I got my boat, first thing I did was to replace all of the fuel hose. I got mine at AutoZone. Someone on here is likely to tell you that it i$ not marine rated... and they would be correct for $ure. :D
 
Apr 5, 2015
50
Islander 26 Little Creek Navy Base
My Islander 26' had a Atomic 4 when manufactured in 1977. The Atomic has long since been removed, and one of the owners installed a bracket and outboard (Tohatsu 8 HP).

The Tohatsu draws fuel from the original tank..... at least 4' upward on a loop on a 7-8 foot line, and comes out through one of the vents. It has been operating fine for years.