How To Install: Cycle Standard Blackbird Legacy Gas Tanks On A Harley-Davidson Sportster
Today we are going to be installing a Cycle Standard Blackbird Legacy Legacy Slimline Gas Tank on a 2006 Harley-Davidson Sportster. Most of this information will work well for installation on 86 to 03 models as well. You can refer to our tech tip on how to install a Cole Foster Gas tank if you are installing a Blackbird Legacy Gas Tank on an 07 and up Sportster with EFI for help with the fuel filter module replacement. Hard to imagine when reading, watch our full video how we install a Blackbird Legacy Gas Tank with very detailed instruction.
Blackbird Legacy gas tanks fit 86-03, 04-06, and 07 and up Sportster models.
Blackbird Legacy Slimline Gas tanks fit 86-03 and 04-06 Sportster models. Plus we offer a universal tank, which means you will need to fabricate mounts to fit your specific motorcycle. The Black Bird Slimline Gas tanks cannot be used with EFI.

Tools needed for the job:
A flathead screw driver
3/8 Inch drive ratchet
Socket wrench extension if needed
1/2 inch wrench
1/4 inch allen socket
Always pressure test a new custom gas tank and do a trial fitting on your bike first before sending it off to paint. Tanks are pressure tested at the factory, but it is highly recommended you or your painter pressure test it again before painting; it's cheap insurance! This will also save you from any fitment issues or surprises causing paint damage or touchups.
Removing Old Tank
- First step, remove the seat, this model has a Biltwell HB Black Diamond Seat
Step 1: Remove your seat for easy access to the bolt on backbone of the frame. This also leaves room to move the tanks on and off a lot easier.

Step 2: Remove rear bolt from backbone of the frame holding on the tank using 1/4 inch allen socket and 1/2 inch wrench.

Step 3: Remove front bolt holding the tank on using 1/4 inch allen socket and 1/2 wrench.

Step 4: Check if the tank has an anit-vapor valve hose attached to the tank. Unplug the anti-vapor valve hose from the tank.

Step 5: Using a flat head screwdriver, loosen hose clamp on the fuel line and push it down past the nipple of the petcock. Pull the fuel line downward and it will unplug from the petcock. *Make sure to turn petcock to the off position before removing the fuel line.

Step 6: Unplug the vacuum line from the petcock. This is located behind the fuel line nipple. (This doesn't apply to all models)

Step 7: You can now remove that old generic stock tank from the bike. Lift up and pull backwards away from the triple trees, you can put a rag on the trees or on front of the tank to help from accidentally banging it up against anything.
Installing Blackbird Slimline Tank

Step 8: There are two options here. You can remove the old stock petcock from the old stock tank after draining out the gas and reuse it or you can replace it with one of our many 22mm petcock options we have available on our website. We chose to install a Cycle Standard straight petcock to get rid of the extra vacuum line.

Step 9: If you switched to a different style petcock that doesn't have a vacuum line, you must remove the vacuum line from the carb and plug the hole before installing the new tank. The line is located on the top of the carburetor behind the main cover and to the right. You can get a small rubber plug at any auto part store.

Step 10: It is now time to put your Blackbird Slimline gas tank on the bike. Be careful while lining up the holes and be sure that the coil mounting bracket is sandwiched in between the two front tank brackets. There are actually little square notches that should lock the coil into place with the frame. We suggest using some masking tape or a soft cloth on your tank and or triple tree, so you don't scuff your nice new paint job while installing.

Step 11: Blackbird and Blackbird Slimline gas tanks come with new hardware. You can reuse the old hardware if it's in good condition. Start with the front and loosely tighten the front bracket using 1/4 allen socket and 1/2 inch wrench. The longer bolt always goes in the front.

Step 12: Securely tighten back bracket with hardware using 1/4 allen socket and 1/2 inch wrench. The shorter bolt goes in the rear bracket. Make sure to go back and securely tighten the front bolt.

Step 13: Fit the fuel line over the petcock nipple, move the hose clamp as close to the top of the fuel line as possible and securely tighten with a flat head screw driver.

Step 14: Plug in the anti-vapor line into the nipple of the Blackbird Slimline tank securely. Bolt your seat back on, filler her up with some gas, put your gas cap on and "GO FOR A RIDE!"
Before and After
Stock Harley-Davidson stock gas tank versus the two styles of Cycle Standard Blackbird Gas tanks.
- Over top view before and after, stock tank versus Blackbird and Blackbird Slimline Gas tanks.- 3/4 view before and after, stock tank versus Blackbird and Blackbird Slimline Gas tanks.
- Front 3/4 view before and after, stock tank versus Blackbird and Blackbird Slimline Gas tanks.

- Side view before and after, stock tank versus Blackbird and Blackbird Slimline Gas tanks
If you need more help with this install on Blackbird gas tank, take a video journey with Todd himself as he walks you through this install.
Check the tech tip how we install a cole foster gas tank as your reference
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