If the bike seems to be running good and no visible signs of fuel (leakage) I'd look to the tank itself. Could be you're not filling the tank all the way or the gas line in the tank is too high. If there is a reserve on the bike that should be looked at as well to make sure it's correctly installed.

 

Thanks a lot everybody!
I don´t know much about mechanics, so I think the best thing to do is to take it to a pro hehe...
The thing is: I think and I´m hoping it´s not a mechanical problem...in four years that i´ve had the bike I had just put 1000 miles and made already the first service...
I feel it runs smoothy, don´t see any black smoke or anything. I just haven´t used it regularly... Maybe that affects the engine or something.
Do you guys think that with only 1000 miles on it it may be a mechanical problem?
I´m really worried of just having half the mileage I´m supposed to

 

With that low mileage (1000) in four years it seems that you don't venture too far from home and combined with whatever your riding habits might be then getting poor mileage is in order. What the mpg's they claim you should get and what you end up with don't happen all the time. Everyone have different riding habits.

 

+1 on the person not filling the bike up all the way. You should be filling the tank up to the opening in the bottom of the bung, (where you screw the gas cap in). Actually, not riding it may/will cause the carb to start clogging up. Yes, your riding style of barely riding it may/will play here too because you'll use more fuel warming the bike up, blippin' the throttle, riding for 10 miles & stopping, and then the whole ruitine back over on your return trip home.

 

I think you have a fuel injected bike. If I remember, 2005 was the last year for carbureted Sportsters. Also, you probably have a 3.3 gal tank. If you just put the fuel nozzel all the way into the tank and stop when the automatic shut off kicks in, you are approximately 1.0 gal from being completely full.

I am not sure when the low fuel light comes on with a fuel injected bike. I know you hit the reserve with the carb bikes at 0.5 gal to empty. My guess is that the injected bikes trigger the low fuel light at 1.0 gal to empty.

That would mean that from fillup to low fuel light you have 1.3 gal of gas. At 50 mpg, that would give you a 65 mile range. Sounds about what you are getting.

Next time, after the pump clicks off, CAREFULLY pull the nozzle out of the tank, hold back the splash ring and SLOWLY fill your tank until gas comes over the lower fill ring. Then you will be full. Do the same on the next fill up and manually calculate your mileage. You will be pleasantly surprised.

 

Thanks a lot guys,
I checked and it is still a carburator engine...
I talked to the HD guys and they have NO straight answer... The just said: bring it and we´ll check it.
The big issue here is that as long as i remembered, my bike has always given me the same mileage per tank (around 80 or 90) so I think it may not be a mechanical problem, but a human issue... Maybe as some of you said i´m not filling the tank all the way to the top, or my riding habbits may affect it...
So what do you think? should I take it to the dealership and have them take a look at it? or should I try filling it to the top and changin my riding habbits a bit

 

One more thing,
When does the fuel light turns on? that may help as well... i´ve never seen it on

 

Can't believe no one asked this question...

How many gallons are you putting in per fill-up? If it's 2 - 2.5 in a 3.3 gallon tank, that's about right.

 

You are correct...it is a human issue. Every night I go over to your house and syphon a little gas from your tank.

 

It is a 4.5 gallon tank and I fill it up to the top. that sohuld give me around 180-190 miles per tank (according to the specs)... Im just getting aroun 80 miles per tank. It sucks!!

Anyways, I took the bike yesterday to the shop and they´ll take a look at it... They said it is the first time anyone has had an issue with fuel consumption... Hopefully they´ll fix it.

I will let you all know what was the problem when i get it back (if there is a problem at all)

Once again, thanks a lot to everyone for your help!