I have a 2007 Fatboy and I've been hearing a hissing noise coming from what sounds like the fuel tank. I understand about the fuel pump pressurizing the system when the bike is first turned on. But this hiss is on all the time when I'm riding.

Plus, I seem to remember the initial fuel pump noise more of a hum where this sounds like pressurized fluid flowing. And it's loud enough to be heard over the engine.

The only time I don't hear it is when I'm off the throttle. If I twist the throttle or keep it constant, I hear the hiss.

Any idea what this could be or what I should check out first?

Thanks,
LeonD

 

Sound like you have holes in the internal fuel line. There are 2 fuel lines connected to fuel pump and check valve. Usually the check valve line is the prob. due to rubbing against the tank. The hissing noise is usually louder when tank is empty. Test is with the off switch when bike is running you prob. will hear wind down hiss noise.
Check valve line is $30 but will have to drain the tank and remove fuel assembly...2-3 hrs. job. Good luck!

 

Thanks for the info. I'll start there first.

LeonD

 

he's right on fuel line making noise in the tank. I had a 03 FLSTCI and it made a noise which wound up being one of the hoses in the tank. there's a supply and a return line. I had the dealer change it and it was around $80. it had worn through and was spraying fuel inside the tank they told me. they also said it wouldn't of been a problem as it was the return line but still wasn't right.