Gas tanks

What size gas tanks is everyone using in their jet jons? I was planning on using 2 Kawasaki 550 tanks but then I came across an aftermarket oversized 550 tank. The oversize tank is around 6 gallons.


Sent from my iPhone using Tapatalk

I'm running 2 tanks, 11 gallons each.

Since my engine is a 4 stroke, and it uses an electric fuel pump which is quite expensive, only my port side tank has a fuel pump. So, how do I get the fuel from one tank to the other? Good question! Getting this to work correctly required some trial and error. I welded fittings near the bottom of each tank, so I could install an equalizer hose that would allow the fuel to flow to the other tank and seek its own level, at least in theory.

But after a few runs, I found that my port side tank would be almost empty, while the starboard side would be about 3/4 full. So, to fix the problem, I installed check valves on the fuel vent lines. On the starboard side, the check valve is oriented to only allow air to flow in, but not out of the tank. Heat/expansion, etc creates pressure, which forces fuel to the other tank. On the other tank's vent line, the check valve is oriented to allow the air to escape, but not flow back in. This lets the pressure off, and keeps it from pulling a vacuum on the port tank. Set up in this manner, it works as intended.

I get around 50 miles on 10 gallons of fuel, and burn roughly 3 GPH at cruising speed. That's pushing a 1648 with a 160 HP Yamaha FXHO.

How do you make room for those tanks? The ski I tore apart had a 10 gallon tank but I can't see it fitting anywhere in my boat


Sent from my iPhone using Tapatalk

I am using the stock yamaha 10 gallon tank.

Boz Mon said:

How do you make room for those tanks? The ski I tore apart had a 10 gallon tank but I can't see it fitting anywhere in my boat

Click to expand...

I put them on either side of the engine, like so:






But, because the tanks are square, and the boat's gunwale is angled, this poses a problem with your poly fuel tanks. Not enough room. Which is why I took 13 gallon factory aluminum tanks, and modified them like this:



When I had the 2 stroke engine, both tanks were at the stern.





FYI.....don't put foam sheeting or expanding foam where it is in contact with aluminum tanks, like I did (not knowing better at the time) It will quickly cause corrosion. Fortunately, I caught it in time. Cleaned up the corrosion, then an etch with phosphoric acid, and then painted with Interlux Interprotect barrier paint, which is impervious to just about anything. Also made sure to use square aluminum tube under the tanks, to get them up off the floor, and used a strip of heavy duty rubber where the fuel tank mount meets the tubing that it sits on.


When I went with the 4 stroke engine, due to the head pipe and water box locations, I had no other choice but to shift the port side tank forward, to make room. But it worked out just fine:




I also had to modify that port side tank for the fuel pump. Basically made a flange with the corresponding hole pattern for the fuel pump to bolt to. I don't have a picture of that modification right now, I'd have to dig through some of my pics to find it.

28 gallons don't worry about running out. You burn gas with these things.

Best to install tank so that filling overflow runs off, not into the hull. This is what drove my tank's position (OEM Polaris 10 gal poly tank) to have filler neck at transom.