Underfloor fuel tank

[ggg]

Hi All. I'm looking at getting an underfloor fuel tank put into a Quintrex 420 Renegade tiller steer. The motor is a 40hp Yamaha two-stroke and I'm looking at around a 100l tank with some normal outboard tanks as extra. What would be the process of installing a tank. I know where I can get the tank and have it welded in, but I don't understand the process of plumbing it though. Would I need a fuel pump to pump the fuel to the motor? The fuel lines would be around 3m. How would I check the fuel level without gauges and what else do I need to know? Thanks

[Jimmyjack]

It will draw through the line without a fuel pump I think, althoughyou have to be careful your lines dont get tiny cracks or splits.

You have to have a dedicated breather valve built in to the system so the gas can escape on a hot day.

You can either have a sender built in to the tank which then requires a gauge to read fill level, or you can use a piece of dowel down into the tank when you want to check the level. I  use dowel on mine but I would love a sender etc but it's no big deal really. Gradually you learn how muuch fuel you use per hour and how much you have left. 100 litres equates to over 100kg which means another person in weight, and if that goes up the front that can change the dynamics of your boat ride and handling.

[The Mad Hughesy]

56 minutes ago, Jaz44 said:

Hi All. I'm looking at getting an underfloor fuel tank put into a Quintrex 420 Renegade tiller steer. The motor is a 40hp Yamaha two-stroke and I'm looking at around a 100l tank with some normal outboard tanks as extra. What would be the process of installing a tank. I know where I can get the tank and have it welded in, but I don't understand the process of plumbing it though. Would I need a fuel pump to pump the fuel to the motor? The fuel lines would be around 3m. How would I check the fuel level without gauges and what else do I need to know? Thanks

that is some serious fuel for a boat that size. what kind of trips are you planning to use it for?

[ggg]

I need the fuel tank size for big reef trips. I won't have the tank under the casting deck, it will be just foreward of the centre of the boat.

[kmcrosby78]

Good luck with the process mate, hope it all goes well for you.

[The Mad Hughesy]

19 hours ago, Jaz44 said:

I need the fuel tank size for big reef trips. I won't have the tank under the casting deck, it will be just foreward of the centre of the boat.

that sounds like alot of fun. good luck to you man!

 

depending on the location of the tank, you could always cut a hatch into the floor which could be above the fuel tank gauge

[Drop Bear]

I have an underfloor tank and the fuel gauge doesn't work. I make do by taking 2 x 10 ltr cans. 

The fuel will vacuum pump into the engine, just make sure all your seals are in good shape including the o-rings on your fuel filter/s

[ggg]

Thanks for the ideas. I might see if I can flush mount a fuel tank gauge. If not, a dowel will always work.