How to Replace an FXR Gas Tank (Step-by-Step Guide)

If your fuel tank is rusted, leaking, dented, or you’re upgrading to a stretched style, learning how to replace an FXR gas tank can save time and money. The FXR platform from Harley-Davidson (1982–1994) uses a straightforward mounting setup, making this a manageable DIY job for most riders.

This step-by-step guide walks you through safe removal and installation — plus tips to avoid common mistakes. Genuine OEM Harley Davidson FXR Center Fill Red Gas Tank FXRT FXRS

Tools & Parts You’ll Need

Before you begin, gather:

Socket set & ratchet
Combination wrenches
Torque wrench
Screwdrivers
New fuel tank (FXR-specific fitment)
New fuel line (recommended)
New petcock gasket or O-ring
Thread sealant (fuel-safe)
Clean shop rags

Tip: Always confirm your tank matches your exact FXR year (1982–1994) and carb/EFI setup before starting.

Safety First

Work in a well-ventilated area.
Keep away from open flames or sparks.
Disconnect the negative battery terminal.
Drain as much fuel as possible before removal.

Fuel vapors are flammable — take your time and work carefully.

Step-by-Step FXR Gas Tank Removal

Step 1: Remove the Seat

Locate the rear seat mounting bolt.
Remove it and slide the seat backward.
Set aside safely.

This exposes the rear tank mounting point.

Step 2: Turn Off the Fuel Supply

Switch petcock to the OFF position.
Disconnect the fuel line from the carburetor.
Use a rag to catch any remaining fuel.

If your tank still has fuel, drain it into an approved container.

Step 3: Disconnect Fuel & Vent Lines

Remove the main fuel line.
Disconnect any vent or overflow hoses.

Label hoses if needed to avoid confusion during installation.

Step 4: Remove Mounting Bolts

FXR tanks typically use:

Front mounting bolts
Rear mounting bolt (under seat area)

Loosen and remove all mounting hardware carefully.

Step 5: Lift Off the Tank

Gently lift the tank upward.
Tilt slightly to clear frame tabs.
Inspect frame mounting points for cracks or wear.

Now is a good time to clean the frame area.

Installing the New FXR Gas Tank

Step 6: Inspect the New Tank

Before installation:

Check inside for debris
Flush with clean fuel if necessary
Inspect welds and mounting tabs
Confirm petcock threads are clean

If installing a new petcock, apply fuel-safe thread sealant.

Step 7: Install Petcock

Thread petcock into tank carefully
Do not overtighten
Ensure proper alignment for fuel line routing

Allow sealant to set if required.

Step 8: Position the Tank

Place the new tank onto the frame
Align front mounting tabs
Install bolts loosely at first

Do not fully tighten until all bolts are started.

Step 9: Tighten Mounting Hardware

Align tank evenly
Ensure proper seat clearance
Torque mounting bolts evenly

Proper alignment prevents stress cracks over time.

Step 10: Reconnect Fuel & Vent Lines

Reattach main fuel line
Secure vent hoses
Double-check clamps

Turn petcock to ON briefly and inspect for leaks.

Step 11: Reinstall Seat

Slide seat into position
Install mounting bolt
Confirm tank and seat alignment

Final Inspection Checklist

Before riding:

✔ No fuel leaks
✔ Proper bolt torque
✔ Fuel line securely connected
✔ Petcock operating smoothly
✔ Tank centered on frame

Start the engine and let it idle while checking connections again.

Common Mistakes to Avoid

Reusing cracked fuel lines
Overtightening mounting bolts
Forgetting new petcock gasket
Installing tank without checking seat fitment
Skipping leak inspection

Taking a few extra minutes here prevents long-term problems. Genuine OEM Harley Davidson FXR Center Fill Red Gas Tank FXRT FXRS

How Long Does It Take?

Most riders can complete this job in 45–90 minutes, depending on experience and whether the tank requires petcock installation or minor adjustments.

Should You Replace or Repair an FXR Gas Tank?

Replace your tank if it has:

Severe internal rust
Fuel leaks
Structural dents
Cracked mounting tabs

A new direct-fit FXR gas tank improves reliability, fuel delivery, and overall appearance. harleydavidson.com