Join Date: May 2010
Location: Calgary, Alberta, Canada
I did this with my 'C' and I can tell you it was a bit of a failure. First, I plumbed the aux fuel into the plate the fuel pump is attached to. It took some experimenting, but I got a good seal, no leaks. I JB welded an on/off fuel valve on the flat section of the tank. This valve turned easily and didn't take a lot of stress. Next I bought a bag for the luggage rack in the back to put the tank into. It helped hide it. Plumbed the fuel to a QD pair and I was off.
The failure part. I purchased the tank as a sealed vented tank. That is the tank vented through a vent hole but the tank/cap was supposed to be sealed. Such was not the case and the tank splashed fuel all inside the bag. It was a real mess. The tank vendor really screwed up on that one, and it made the entire venture far less appealing. I added a filter to the outlet of the tank and the fuel flow was far less than ideal. If I had it to do again, I would verify the cap sealing, and I would add a pump, like a transfer pump. That way when you get to 80 or 90 miles, you can just hit the valve and pump and let her go. As it was I only filled the aux tank to about 50% to avoid the splash leaks, and turned on the transfer valve after 10 or 20 miles. This way the aux tank would have more than an hour to slowly drain into my main tank. This worked pretty well, I only wished the aux tank hadn't leaked so bad. If the aux tank cap hadn't leaked so bad I would have added a pump and called it good.
Why did I even start this? Well, the same as you, I wanted to get more range out of the bike. I was riding to Sturgis and we had planned on some back road riding with and expected distance between fuel stops at more than my capability of 130/140 miles. I needed more range and tried this. I did get an extra 1.5 gallons or so, as far as I wanted to fill the splashy leaky tank, so it did serve a purpose. In the end I dismantled the entire affair, and sealed up the hole with a bolt, nut, washers, gasket material and some gas tank sealer (Seal-All). I just wasn't worth all of the mess. If I had it to do over, I would have found a container or containers I could have carried an extra couple of gallons of fuel in and simply stopped and topped up the tank as needed. You can get these that look like water bottles of 1 or 1.5 quarts. Stash a couple or three of these and call it an emergency stash.
The guys I was riding with loved to jab me about the small tank on the Honda, but hey, it is what it is. None ever refused or were upset that we had to stop because I needed fuel. Every stop, they would ask how I was on fuel and had an idea of how far before our next stop. There was me, and a young lady on a Sportster. She had a great sense of humor and we joked about it with each other every stop. At least I had company. On the way down and back it was just us guys, but both were my age and grateful to stop and pee anyway.
'12 Road Glide Ultra, Kuryakyn Alley Cat intake, Jackpot Super Duals header, Jackpot HiRoller mufflers, PV Tuner, Daymaker LEDs