Motorcycle Tank Fabrication Parts

MOTORCYCLE TANK FABRICATION PARTS FOR CUSTOM AND DIY BUILDS

Building a custom gas tank from scratch or modifying an existing one requires a specific set of hardware that most general suppliers do not stock. Petcock bungs in the correct thread, filler cap bungs and caps, fuel sight gauge kits, Frisco tunnel base plates, and rubber mounting kits are the parts that turn a raw steel tank shell into a finished, functional piece. This collection covers all of it, made primarily by Lowbrow Customs in the USA, alongside Cycle Standard.

PETCOCK BUNGS

The correct petcock bung thread depends on the petcock being used:

• 22mm bungs: The standard thread for Harley-Davidson petcocks and most common aftermarket fuel valves. Standard length and Frisco long style for tanks where the standard bung sits too shallow for the petcock's thread depth. The Frisco long variant is purpose-built for tanks mounted high on the backbone where additional thread engagement is needed.

• NPT bungs: 1/4 inch NPT and 3/8 inch NPT steel weld-in bungs for tanks running NPT-thread petcocks. The 1/4 NPT pack of 4 is one of the more reviewed pieces in the collection. Tophat-style 1/8 inch NPT bungs for breather or fitting applications on the tank body.

All Lowbrow Customs petcock bungs are 1018 steel, weld-in, and sized for a clean press fit before welding.

FILLER CAPS AND CAP BUNGS

Lowbrow Customs makes custom filler caps in brass and aluminum with multiple finish and venting options:

• Caps with weld-in bung: Brass and aluminum vented filler caps that include the weld-in steel bung as a single purchase. The cap and bung are matched for correct fitment. Available in vented and unvented configurations, and a cast aluminum spinner version for a more decorative cap profile.

• Caps without bung: Sold separately for builders who already have a bung in the tank or are building around an existing filler neck.

• Loose bungs: Weld-in steel and aluminum bungs for 1-5/16-inch filler caps, for builders who need just the bung to fit a cap they already have.

• Pop-up caps: Cycle Standard flush mount pop-up gas caps with integrated weld-in bung in chrome and polished stainless. The Cycle Standard thread-in style filler neck bung covers 1996-up Harley-Davidson thread-in cap applications.

FUEL SIGHT GAUGE KITS

The Lowbrow Customs DIY fuel sight gauge kit adds a functional fuel level indicator to any custom gas tank without a stock gauge sending unit. The kit includes two 1/8-inch NPT mild steel tophat bungs that weld into 5/8-inch holes drilled on the front face of the tank, USA-made 90-degree chrome or brass fittings in 1/8-inch NPT to 1/4-inch hose barb, polished USA-made stainless hose clamps, and 12 inches of 1/4-inch ID clear polyurethane fuel line. Available in brass fittings and chrome fittings versions. The completed gauge gives a visible fuel column on the side of the tank without penetrating the tank face with a sender or gauge.

MOUNTING HARDWARE AND DIY TANK SHELLS

• Frisco mounting kit: Lowbrow Customs universal Frisco gas tank rubber mounting kit with aluminum inserts and flat head Allen hardware. Suits custom chopper and bobber builds running a Frisco-position tank on a frame backbone without a dedicated stamped mounting bracket.

• Frisco tunnel base plate: Cycle Standard DIY Frisco mount custom gas tank tunnel base plate for builders fabricating their own peanut or Frisco tank from scratch. Provides the correct tunnel geometry at the base without building the curve from flat stock.

• Wassell peanut tank shell: Cycle Standard DIY Wassell peanut gas tank shell, raw steel, for builders who want to build a complete peanut tank from a correctly shaped shell rather than starting from flat sheet.

• Triumph oil tank mount: Lowbrow Customs rubber mount bracket kit for Lowbrow oil tanks on 500 and 650cc Unit Triumph motorcycles, with brass washers. One of the most reviewed pieces in the collection for Triumph builders.

Browse motorcycle gas tanks for finished tanks alongside these fabrication components, and motorcycle petcocks and motorcycle gas caps for hardware to complete the tank setup.