Fat Tank

Here are pictures of my bike with the Fat Tank I got from an outfit in Orange, CA. (Here is their ad.) I put it on my 1997 Honda Magna in August, 1999. Click on a picture for a full-size version.

I got this tank from these nice folks:

Fat Tank
Dale J. & Joan T. Hammond
982 North Batavia
Unit B-2
Orange CA. 92867
Phone 1-800-582-2274 or (714) 744-4722

I got it because I couldn't stand the short range of the Magna: with 120 miles maximum range, fuel was a constant, nagging concern. I would sometimes have to fill up at 60 if I wasn't sure of the next 40 miles. (Not uncommon on the back roads of California's ranch country.) The new tank's capacity is five gallons, plenty for those long trips into the unknown.

The Fat Tank is bulbous. It's not necessarily ugly, but that's what you think at first. It's wider than the stock tank, flatter on top, and it sits higher and flatter on the bottom, too. Sitting on the bike, you'll never see your chrome "airbox covers" or your ignition key again.

I had the tank painted during a rainy week in the first part of 2000. I got it painted a dark, metallic blue. It doesn't clash too badly with the stock (black) fenders and side covers, and it matches my helmet. This picture is kind of strange because it needed a lot of work to bring out the color of the tank. The other pictures on this page are from before it was painted, when it just had a few coats of "primer gray" for protection.

Since the tank is wider than the stock one, windshields that normally fit the Magna might need to be trimmed down some. My new Memphis Shades "Malibu" needed a lot of work with a grinding bit on the drill to re-shape the lower curve.

The Fat Tank people start with a Harley two-lobed tank -- inside it's originally two separate tanks with a divider down the middle. (That's why there are two filler caps.) They cut the tank apart and remove the divider, then weld it all together again. Then they weld on the three mounting points: two brackets under the center, and a "tail" that bolts to the frame under the front edge of the seat. Finally, they smooth out the looks a little with Bondo.

The tank fit on the bike perfectly. Everything sits where it's supposed to, the bolt hole lines up, etc.

I was not happy with the venting (or lack thereof) in the tank and filler cap, so I drilled out the diaphragm in the "one-way" vented cap. Now the cap breathes both ways, which prevents overpressure inside the tank and also lets air in to replace fuel.

The tank and accessories (filler caps, petcock) will run you over $800. This sounds like a lot, and it is. But the lack of range bothered me so much that it was either this, or get a different bike entirely. I would have been more than $800 out of pocket doing that, what with the cost of selling and buying and the accessories I couldn't carry over, and I love the Magna so much I didn't want to switch. So I decided that for me, it was worth the money.

The price they advertise is for the tank alone. You'll need more to make it a working system. First you need a pair of filler caps: the right-hand one is the "real" one, and the left is a plug for the opening to the original left-hand lobe. They'll sell you a set, asking you to choose from the usual Harley menu of price vs. fanciness. You also need a new petcock to let the fuel out: your original one is the wrong size. They'll sell you that too.

Finally, you'll have to go to an auto parts store and buy some fuel hose and brass adapters: the fuel line coming off the petcock is 1/4", but the original plumbing on the Magna is 3/8". Don't worry, the 1/4" feed doesn't starve the engine. I had to construct a coupling from three separate brass pieces: a 1/4" nipple, a 1/4-to-3/8 thread coupler, and a 3/8" nipple. Total cost of the coupling and hose is less than $10, but finding the right parts is the tricky bit.

The new petcock is on the right side of the tank. I figured the safest thing was to leave my original plumbing intact as much as possible, so I routed the 1/4" hose across the rear cylinder heads coupled it to the original 3/8" hose on the left. I put the fuel line inside a short length of radiator hose for extra heat and abrasion protection.

I didn't know about all this hose-and-coupling stuff before I bought the tank. I called and talked to the folks in Orange before I ordered, and they didn't say anything about the plumbing and improvisation that was required. They said the tank would fit the bike, and of course it does. But the right-hand petcock and need to adapt the plumbing came as a surprise. For a "bolt-on" I was expecting it to line up and accept the existing fuel line, or at least some instructions and guidance in the kit. This was my first foray into fuel-system customizations and I didn't have a lot of confidence. But I am reasonably handy with tools and after a call to Orange to check my plan and a visit to the auto-parts store, it came together without any problems. The hardest part was screwing the brass fittings together: without an extra-long socket of the right size, I wouldn't have managed it. They could improve the product by including instructions and a parts list for mating to the bike's fuel system, even if they don't include the parts. Maybe there are liability problems if they do this.

The bottom of the tank is pretty flat, and the reserve on the new tank is quite small: under 1/2 gallon. This is controlled by the petcock, by the distance from the "main" feed height to the "aux" feed height. A different petcock would go on reserve sooner, giving more notice before you run out of fuel entirely. I got 200 miles before reserve once, the farthest I've tried it. But I like high speed and big windshields, so I get rotten mileage. Now I always plan my fuel stops at 175 miles or less.

The tank gets a lot of attention: everybody asks about it. Many Harley people have to puzzle over seeing a Harley tank on a Japanese bike. At least I've painted it, so it's not Primer Gray any more.

Back to Allan's Magna page.

Last modified June 28, 2000 - apratt@netgate.net