The idea came about from our riding group doing extended day rides. The long distances required us to find fuel wherever we could. This was even more difficult when riding in protected areas where fuel spillage becomes an issue. This system is very simple and it works without the use of pumps, instead working solely on the vacuum created in the main tank vent hose. The main fuel tank draws from the auxiliary tank first. This way also cuts out any chance of fuel spillages while transferring fuel from jerry cans being carried on the back.
This walk-through is the first one I made using an older style fuel cell fitted to the swim platform of my own Kawasaki Ultra 300X, I have since made others using a newer style tank, and many others here in Australia have since copied the idea (with my permission) to their own skis. Many have had no mechanical knowledge and have found it very simple to replicate.
Below are the steps necessary to replicate this very easy-to-install auxiliary fuel tank to your runabout. It shouldn’t matter if it’s supercharged or not, the fuel delivery system remains the same.
[Above: Next, fit the fuel cell to the rear of the ski. The tank most commonly used holds 45 liters. On any of the Kawasaki’s this is easy because the rear deck is flat, on other branded skis heavy foam packers can be glued to beneath the tank to level it out. I have made a custom ratchet webbing strap to firmly hold the fuel cell in any rough conditions.]
[Above: Next is to connect the 6mm fuel rated hose to the rear tank pick up and another to the vented fuel tank cap. Find or make an entry point in the rear of the ski, once again Kawasaki have made this easy with the rear vents being utilized. Others have drilled holes and used grommets when not in use.]
[Above: You then fill your OEM tank on the 300X (this is 82 liters to the filler neck), fill the accessory tank (of which, is 45 liters). This gives a total capacity of 127 liters. As you ride your ski the vacuum created in the OEM tank draws the fuel from the rear tank utilizing your unchanged OEM vent line with the non return valve still in place. Once the rear tank is empty the system is no different to OEM the air is now being pulled in the vent line via the rear tank.]