Hey all! Over the past two days ive encountered an issue with my 09' Nightster fuel light ... and don't worry, this isn't a "is it supposed to come on at x amount of miles" thread.

So anyway, my girl and I took the bike yesterday to Ocean City, NJ to spend the night. As always, before we hit the highway I fueled up so id have no concerns on the journey. Well anyway, about 10 miles and into the highway my fuel light comes on! Right away I hit the first rest stop to make sure I wasn't somehow leaking fuel because I knew I had a full tank. Wel after spending a few minutes checking, I was unable to locate any leaks and my gas cap was fit snug so I started up my scoot, and wouldn't ya know ... the fuel light was out! So I brushed it off as a freak occuance and we continued our journey. But another few miles down the road, the damn fuel light comes on again! Well we continued on our way with no actual fuel problems, but the light was on the entire way. It did the same thing today too... The light is out when I start the bike, but a few miles down the road it comes on. Anyone have this same problem? Is the fuel sensor going bad?

Thanks in advance for your replies!

 

I had the same problem with my 2010, it only seems to happen if I get on the interstate right after I fill up. During my cruising around town it only lights up when I am running low.

I did open the cap while driving down the interstate to look in the tank, probably not the smartest thing I ever did but whatever.

 

Thanks for the reply Robo! Interesting to see im not the only one that's encountered this problem. I know there's a ton of Nightsters here... anyone else experience the same?

 

I had it happen once but not issues since. I fueled up and left town and was on a state highway doing about 55. Was on for about 30 miles i got to my buddies house and then shut it off. When I went to show him it wouldnt do it again. IDK...maybes like jeep its a 1200N thing lol

 

I believe the light is activated by a floating device attached to the petcock/ fuel pump assembly in the tank.

Could be the gasoline has built up a varnish and the float is sticking.

Without disassembly, run some Chevron Techron though a tankful or two. Also changing brands of gasoline that you use can help keep the system clean.

Any of the name gases -Chevron, Shell, 76, Exxon etc are good. Costco and not top tier fuels maybe not as good.

 

Sometimes my light comes on after 40 or 60 miles, then goes off and comes back on around 90 like it should. Just use your one of your trip meters, you have 2 of them.

 

Mine will turn on at empty, half tank, and even right after a fill up. I just don't listen to it. i go strictly off the trip odometer. If i had it my way, i'd just cut the wire to the light that activates that false positive low fuel indicator. General rule for my Iron: fill up every 100 miles.

 

Thanks for all your replies. Glad to report that I've since put a few hundred miles on my scoot over the past few days and the light hasn't given me any problems. Maybe its just a highway thing?

 

It may be that the sensor got gummed up and is now working OK. The low fuel warning light trips on my Sportster very consistently at 135 miles. I have plenty of gas at that point with the 4.5 gallon tank.

Because I know I still have plenty of fuel to run with, I don't always fill up when the sensor trips. Ive noticed that once it hits the 135 mile mark or very close it will not come on right away on a restart, but will go a couple of miles before illuminating again, until I finally refill the tank. It seems to have a built in delay on restarts.

 

Happens at random on my 09C 1200C. I can fill it up to the top and it'll turn on right away. I'll get down to 1 gallon and it won't turn on. I went from using 91 octane to 93 and it never turned on. I don't trust it. Just waiting for the dam light to burn out.