Farting sound...seriously

[dude94133]

Weird sound coming from the bike fore sure. After a ride when I turned the bike off, about every 10 seconds of so I heard a "Pffft" sound. It was coming from the left side of the bike and close to the front cylinder/spark plug. Sound continued for several minutes and then I had to walk away !

Any ideas what this could be?

Thanks!
Phil

08 HMS
03 ST4s

[33996]

Pressure bleeding off from the fuel injection system ?

I've heard it too and already assumed thats what it was.

[dude94133]

Hmm. It does sound like a build up of pressure that is escaping. Didn't know the fuel injection system could be the culprit. Never heard this sound before, nor on my ST...

Thanks

[Caidly]

Maybe the bike has gas...

(even more so if it has the CA Cycleworks tank)

[hyperdookie]

Never heard it on mine but I suspect crankcase pressure.Is that possible?Next time you shut it down,unscrew the oil filler cap and see if it stops.Could also be fuel tank pressure?Try the same with the gas cap.

[MTScott2]

Sure cure BEANO

[MarksFriggin]

Try slowly removing the fuel filler cap next time you hear the noise. I've noticed that sometimes there's a build up of pressure in my tank. I've never heard this noise you describe though.

[33996]

I got curious so I went out and checked on my hyper. Ran the bike to warm up, took a short burn and came back and listened. The sound your talking about is pretty quiet, but in my empty garage with nothing else going on you can hear it.

The fuel pump return line is bleeding pressure back into the tank, i'm pretty sure this is the noise you too are hearing.

[elliott5]

HYPERFARTS!

Cooooool.