Our friends at Lowbrow Customs teamed up with the ever-talented Cycle Monster for an ongoing series Lowbrow Learnins. Enjoy!
- Install pivot mount with the end pointing up
- Spacer washers if needed (not included in the kit)
( Your frame may have these extra tabs. Don't install the pivot mount here! )
( Install pivot mount here )
These older frames could of been modified over the years. You may need to make adjustments to the frame or to the tank to make things bolt up. Also, make sure to avoid heavy sanding on the edge seams of any tank. Whether you've made modifications to a tank or have a brand new one, it's always great insurance to pressure test the tank before paint to make sure there's no leaks!
* Pressure test a tank at home*
-Plug off cross over tubes with a tight fitting bolt in a hose and hose clamps
-Plug off fill neck(s) with rubber plumbing cap, usually 2.5", and hose clamp
-Plug off any bungs with bolt and thread tape
-Grab a bicycle pump and hose clamp a hose to it. Stuff the other end onto a cross over tube. Don't use your compressor!!
-Pump it about 10 times and start spraying soap water everywhere. Look for bubbles!
Push a 1/4" fuel hose over the vent tube of the right tank. On your bench, hold both tanks together to measure where to cut the hose, tighten up a a hose clamp on the right tank. Slide another clamp over the hose for later.
Tape all the painted edges to prevent chips before install!
Place the left tank on the frame and slide the long bolt through the top tank mount tab. Bring the right tank to the frame and push the vent hose onto the left vent tube. Make sure the hose clamp is snug to make it easier to tighten later. Install the washer and nut loosely.
Make sure that the rear tank tabs (C) are stacked like this. Right side tab is against the pivot mount, left tab is behind that. Use the black allen head to tighten this up. You may need to lift up the rear of the tank to get the threads started.
Line up the lower tank tabs (B) to the frame tab. You may need to adjust the tank tabs to fit your frame if it is modified or bent. Leave everything loose for now. Check for riser and handlebar clearances by turning bars to full left and full right. Look for pinched cables.
Use a ratchet box end or an open-end wrench to tighten the bolts securing the pivot mount. Check the alignment of the tank and center spacing and tighten all other bolts using a long 1/4" ratchet extension, or a long flat tip screw driver, tighten up the left side vent tube hose clamp. Make sure both are tight.
A version of this article was first published on LOWBROW LEARNINS: HOW-TO DIY INSTALL WX GAS TANKS 1936-1984 HARLEY-DAVIDSON BIG TWIN FRAMES