Behind the Seat Fuel Cell w/ -AN Fittings for Jeep YJ

Regular price $399.00
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Check out the Motobilt Jeep YJ fuel tank. This tank is industry leading in that is was designed specifically for the YJ to maximize fuel capacity while retaining the rear seat. Motobilt offers a solution for relocating the fuel tank in your Jeep YJ. There are a few universal options available like the popular RCI 2161a which is basically a rectangular aluminum fuel cell. It was not designed specifically for the Jeep YJ. The Motobilt Jeep YJ fuel tank was designed to fit behind the rear seat and maximize the space behind the seat. It is actually contoured and angled to fit behind the seat.

The tank has a capacity of roughly 18 US gallons. The Motobilt fuel tank is CNC cut from 1/8 inch 5052 aluminum and formed on a press brake. The tank is TIG welded for ultimate strength. The tank includes a large D-ring style cap. This can be converted to remote fill by purchasing a different filler neck system that utilizes a 12 bolt, 5.38 bolt circle flange.

The optional 2 clamp down bodies capture the top and all four sides of the tank and bolt securely to the mounting base. These parts are CNC Laser Cut but from 16 gauge steel. The parts are formed on a hydraulic press break. This mount will ensure your fuel cell is mounted securely. The Motobilt tank features three number 8 -AN fittings on top of the tank which are tig welded into place.

  • Jeep YJ behind the seat fuel tank for use with external mounted fuel pump.
  • 3 Number 8 -AN fittings on top of the tank which are tig welded into place
  • Designed to fit behind the rear seat
  • CNC cut from 1/8 inch 5052 aluminum
  • Press brake formed
  • Tank includes a large D-ring style cap
  • 18 US gallons capacity
  • Optional Mounting brackets available part number MB5000-Mount

The fittings are for:

  • 1. Vent with an included roll over valve pre-installed inside the tank.
  • 2. A return line.
  • 3. A pick up tube. The pickup has a barb fitting inside the tank and rubber hose extending to the bottom of the tank.
  • In the bottom center of the tank we have welded a trap to hold the hose in the center. If you ever need to relocate the tube you can reach through the filler neck opening and move it.
  • This fuel cell is used for applications where you are extending the wheel base and the rear axle would contact the factory fuel tank. It would also be used in situations where more ground clearance is needed. This kit works perfectly with the Motobilt Jeep YJ Back Half Kit where the frame rails are moved up and in for ultimate clearace.
  • The Motobilt YJ Behind the Seat Tank will not fit in the Jeep TJ. It would have to be cut and clearanced in a few places. We plan to fabricate one specificly for the TJ at some point in the future.


  • We have developed a mount specifically for the MB5000 Fuel Cell. The kit consists of three parts: the main under tank plate and two clamp bodies. The under tank plate is CNC Laser Cut from .125 inch high strength steel plate. Mounting brackets sold separately PN 5000-Mount
  • We recommend using Permatex 80016 Form-A-Gasket number 2 Sealant to seal the contact surfaces. Including the fuel filler cap assembly as the gasket can deteriorate due to ethanol.  


  • 12 1/2"s tall
  • 7"s wide at the top of the tank
  • 10 1/4"s wide at the bottom of the tank
  • 34 "s long


Product Components Filler & Neck Cap Assembly

Why choose Motobilt?

Money Back Guarantee

We stand behind the products we offer.  If you are not 100% satisfied we will replace the part of refund your purchase. We appreciate the business and take pride in building a trustworthy brand.

Made in the USA

We manufacture our products in house using the latest in fiber laser cutting and press brake technology. Unlike most of our competitors who outsource their manufacturing we are able to control our process from raw material to delivery.