hey guys, just bought an 83 sportster xlx and i believe it has an aftermarket gas tank. the tank on the bike has 2 gas caps. everywhere i read on the internet it looks like the bike came with a peanut style tank with one cap. i thought one was for gas and the other for oil, but on the right hand side of the bike below the seat is the oil tank i believe. stupid question, what is the other gas cap located on the left hand side of the tank?

 

I have not had one of those tanks myself but i think i have seen two different ones. For the single tanks it may be a dummy cap that does not even come off. For double tanks it is used to fill the other half. See what others here may say also.

 

Mainly there for decoration.
To some it may suggest (at a quick glance) that the Sporty is not a Sporty at all, but is a big twin.
If both caps come off then just put gas into whichever side you want.........pg

 

The 83 XLX came with the 2.5 gallon single fill tank. It is the traditional shape siilar to the one seen now on the XR1200. The tank you have now sounds like a Fatbob style. It is either a one piece or a 2 piece. becaused of the deep tunnel it will have a cross over on bottom of the tanks towards the front going from tank to tank. If both caps come off then it doesnt matter which side you fill.

 

They call the tank a fat bob and correct they both the caps come off and there should be a cross over fuel line under the tank

 

mine has two caps also both can be used to fill tank my buddy bought a fuel gauge for one side of his

 

Some BT tanks with fuel gauge... that gap that has a gauge isn't meant to be opened.
Gauge will be damaged...

 

it has the crossover line on the front bottom of the tank. the weird thing is i took it for a ride the other day and it died on me. it would crank but kill after a second. i opened the right side cap and it was empty, so i filled it up with gas and it fired up and ran. so evidently i ran out of gas but the left hand side of the tank was full. i'm guessing that the crossover line is clogged or something and not allowing fuel to pass through. that was what the confusing part to me, which is why i asked the question. thanks for the help everybody.

 

Here's the tank that would have come on your bike when it was new.

 

The fatbob on mine had 2 but one is now welded over, it screwed up. On mine there is a crossover. Single on the left & a dual on the right. Someone plugged my crossover & it ran out of gas like yours. It's aggravating.