99-05 softail service manual (and my riding buddies) say I have a 5 gallon gas tank (99% sure it is stock tank).
I've had my Fatboy 03 FLSTFI for 3 years now and have ridden it close 5k miles, pretty sure I ran out of gas pulling into gas stations twice and the tank seems totally full after 4 gallons? I seem to be able to get close to 150 miles from a full tank but usually fill back up after 100-125 or so and usually takes 3.5-3.8 gallons or so.
I've heard people mention bikes having "reserve" gas that you switch over to that?
My questions are:
Do I have a 5 gallon tank?
Did they ever put 4 gallon tanks on these bikes?
Do I have a reserve "gallon" somewhere in the tank I can switch to?
Much appreciated,
Sarge

 

Fuel injected bikes do not have a reserve, the idiot light comes on you should have about 1 gallon of fuel left. Your owner's manual will tell you fur sure, maybe it is a 1/2 gallon.

Those bikes all came with the same tank, which I believe is 5 gallons. But again, owner's manual will confirm capacity. HD had some weird sizes going around, 4.8 gallons etc., so only the manual can confirm the exact size. For reference my 1997 FWDWG has a 5.2 gallons tank, why the extra .2!??!?! Only some guy in Milwaukee knows for sure. Good luck.

 

Per the spec sheets, you have a 5 gal (18.9L) tank. The carbed bikes have a 0.5 gal reserve, and on the EFI bikes, the warning light comes on at approximately 1.0 gal.


I'll add two other thoughts that could affect the tank volume...

First.. If a prior owner added tank lifts to your bike, it will affect your useable fuel volume, due to the tank angle change in respect to your fuel pick-up.... In your small signature pic, it doesn't look like you have them, but hard to tell. The lifts raise the front of the tank from 1.5" to 3". Some like the look because it exposes the rocker boxes more... others believe they help with engine cooling. You can see them easily if you look at the forward mounting bolts to your tank.

Second... I have no idea how much this could affect your fuel fill, and it would vary based on your patience, but the front of your tanks are split. If you developed an issue with your fuel tank crossover hose, like a debris clog or other issue affecting the flow of fuel through that hose, it could affect your ability to top off the left tank when refueling. For example your fill side would look full, but the other side wouldn't be topped off due to the slow, or a failure, of that hose to equalize the two sections.

Both are absolute long shots as possible solutions to what you see happening... but they exist, so I thought I would throw them out there...

For your refueling reference...

I have a 2003 Heritage with a 95" big bore kit, Andrews 26 cams, and headwork. My mileage varies between 35mpg (when I'm playing around with the throttle) to over 40 mpg when casually riding on back roads or while on a relaxed freeway/highway trip..

I track my fuel usage on the Fuelly website and just looked over my fuel use history. I usually refill between 110 and 125 miles, and take around 3 gallons. I've used 3.5 gallons at 145 miles a couple times, and I once refilled at 171 miles and took 4 gallons. I believe on the 171 fuel refill, my low fuel light came on, and I was getting nervous looking for a gas station. I don't recall seeing that low fuel light come on more than a couple times since I've bought the bike new in 2003.

Good luck and enjoy that bike...!!

 

Excellent information hattitude, thank you, great insight.
quick question, I assume the fuel tank crossover hose is located inside the tank and might be difficult to check (besides rocking bike left to right and hoping)?
Any tricks to check it?

 

oh, forgot to mention, I really really do enjoy this bike! Thanks

 

No and yes... kind of...

No.... the fuel crossover hose is external to the tank. it runs between the front of the left half, under the tank and inboard of the frame, to the front of the right half..

Yes.. kind of... many people find removing the tanks on bikes with the crossover hose a royal pain in the butt.... I've had the tank off my '03 Heritage at least 5 times for various things, and I have no problem removing and replacing that fuel crossover hose... I do cut it and replace with a new section every time I remove it..

Here's a pic of the left half tank & crossover hose on my 2003 Heritage..

 

Excellent explanation and picture hattitude, I do see mine, looks exactly like yours. I think I will change it as it can't hurt, maybe some debris or something in there, if you have any tricks/tips to check anything please feel free to share. Looks simple enough to do even with tank in place? I'm unfamiliar with how to release those clamps though? I assume I should run her very low on fuel and try to prop the front end up with a 2x4 or similar to tilt tank back a bit before I change just not to get much gas out in garage and have a filled red gas can available to replace/fill. Am going to go onto J&P cycles now and look for replacement hose. Thinking I will do braided if available as I did on my other fuel line exiting the tank.

left

right

braided chrome style maybe available for crossover too?

 

The crossover is connected from the factory with Oetiker clamps.. I use them and believe them to be superior to regular worm-drive hose clamps. They are NOT reusable and can be a bitch to remove until you get the hang of it. I have a couple Oetiker clamp tools and a box full of varying sizes... so I use them. You can probably find a youtube video or two that shows how to remove them... it would be kind of hard/lengthy to type out the removal procedure....

Here's what I do... obviously after running the tank down low on fuel..

I have a couple fuel hose clamps. I put one each, just past the metal nipples the hose slides onto, on each side of the crossover hose... then tighten them down. There are several types available... some are actual clamps, some look like big plastic hemostats...

I then cut the hose about midway between the two clamps. If you clamped properly, the only gas to leak out, will be in that hose, between the clamps. I then put another, longer section of hose, over the ends (one at a time) directing it to a gas can... I release the clamp(s) and let the tank drain...

At that point I usually re-clamp and pull the tank...

In your case, you could just make sure the tanks have completely drained... then remove the Oetiker clamps, and hose ends. In your case, I would use a wire or pipe cleaner and make sure those nipples are open and not clogged...

Then pop a new hose section on between the nipples, and re-clamp...

I have a roll of high quality fuel hose, 5/16" ID, and just cut a 7" piece, replace the OEM hose, and put the plastic chafing guard back on the hose... I like it because it's black, blends in, and is not really noticeable unless you are looking for it...

The problem with those fancy braided hoses, is they make it harder and more expensive, should you need to remove the tank for any reason. I bought one of those quick disconnect couplers for that crossover hose, but it was far too bulky for my tastes... and I didn't like the way it looked... I had to extend the length of the hose, and route it differently to get it to fit... After I finished, I took it right off, and went back to the basic fuel hose set up, before I refueled the tank..

Some would consider this a lot of work on the "chance" that there is a problem with that fuel hose... From a practical standpoint, I would probably agree. I certainly wouldn't pay to have it done, without solid evidence there was a problem with that crossover hose...

But... if you like to tinker with your bike, it's not really that hard to do, and it would rule that crossover hose out as a possible cause...

Good luck..

 

Thanks hattitude, what you explain makes 100% sense to me. I already YouTubed the clamp and understand how to remove and should get a few (for install and tool bag). I will have to youtube how to install the new Oetiker (thanks for the proper name so I can research) clamps now also. I was thinking the same thing about the braided making future tank removal more difficult and black will blend just right as it does now. Thank you for the fuel hose 5/16" ID size which will make my purchase with confidence. I do like to tinker (and add chrome so my plan now is to watch youtube on how to install Oetiker clamps and if I feel good about that I will do exactly as you have described. I have a busy rest of the week/weekend after today so I will research this week and hopefully address it next week. It would be nice if it is somehow clogged as that would make it all worth while and I would feel like I accomplished an issue that has been on the back of my riding mind for sometime. I'll be sure to let you know.
Thanks again hattitude!