seems odd,,,
had to switch to the reserve while riding the two lane the other day,,
but was surprised that (approx) 2 gallons was all it took to fill?
seemed a bit odd to me.

checked the manual, and if i read it correctly, the FLH's total capacity is 5 gallons (or so), with a reserve of approx 1 gallon.

hmm,, that math does not add up?
If there was about 1 gal in the tank when i got to the station, and all i could add was 2 that means i have a 3 gallon tank. thought it was a 5 gallon tank?
.
The fill is on the right side, and the left cap just spins, and there is a hose underneath connecting the two sides...

I never have been accused as being the sharpest tool in the shed, but wow,,, what am i missing?

thanks ,
marion..

 

Marion, the left side is supposed to open up to fill. I don't know what the issue is that it won't. There were tanks called the "Quick Bob" that had a dummy left cap, but looking at the pictures of your bike, this is not the case.
It sounds as if your left tank is running out and the fuel is trickling in from your right tank, making me think you have a restricted X-over line (the one underneath). Look under your dash panel and make sure you have the upper x-over. That one is to let air in and keeping it from vacum locking.
Al

 

Thanks Al,,
as always, appreciate the guidance...
I'll give-er a look over and report back...
marion..

 

Both caps on stock tanks open w/ a clockwise twist

 

Got to fill both tanks.


Quit making twist-on caps in 82.....I would think on an 84, right side is counter clockwise ...left side is clockwise to open

 

Something to keep in mind with the reserve when you do get it figured out , it's less than a gallon so don't count on having more than about 15 to 20 miles max range depending on the carb if you ever have to hit it .

Tom's right about the caps unless you have aftermarket tanks on it .

 

who would have though it!
a left-hand threaded gas cap. the first one I've ever seen!
thanks Tom84,,

and you guys were right, that left tank is dry....i'm amazed the ol shovel was running at all, considering the carb feed is from that left tank.
still just seems odd. I do intend to check the air and gas feed tubes to ensure they are correct. And will also remember that reserve means reserve.
.
and again, thanks all for leading me down the path to the fix.

marion..

 

This is the kind of fella I like helping. He gets back to us to let us know the resolution to his problem. Remember, left tank is non vented cap, right tank is vented cap.

 

The left handed thread caps are pretty common on these. Not sure if all of them have them but my 93 Heritage does.

If your left tank is dry and the right tank is full then you still have a problem somewhere. When fueling up it will not balance as fast as you add the fuel however it should still be filling the left tank through the crossover tube. I.E. If you sat there long enough and waited for the tanks to balance through the crossover tube then you should be able to fill it from one side. Regarding reserve capacity I kinda found out the hard way that it may not really be much the day I got my bike. From the time I hit reserve to the time it ran out on the freeway I traveled 10 miles. Nowhere near to a gallon reserve. Fortunately my wife was following me and I had put a gas can in the car and it also ended up right at an exit. While she ran and grabbed some gas I coasted to the bottom of the exit and was on my way again a few minutes later.

 

Hmmmm..... That might change what I stated above then. If the left tank isn't vented then it might only work if filling from the left tank if both caps are not open.