Kawasaki Concours Forum

The C-14, aka Kawasaki Concours-14, the new one :) => The Bike - C14/GTR 1400 => Topic started by: thundermax on March 09, 2013, 11:37:35 AM

Title: Gas Tank Pressure
Post by: thundermax on March 09, 2013, 11:37:35 AM
When I park my 2009 in the garage after riding, I hear a hissing/air releasing sound from the gas tank that goes on slowly until all the pressure is released. Guess it builds up pressure during riding. Don't know anything about check valves or purge valves with the fuel system, but I read the only release area is the gas cap. So there is maybe a vent hole in it? If so maybe mine is blocked with dirty or something?

Does anyone else have this sound after parking?

Any other comments about venting and my situation would be helpful. Thanks.
Title: Re: Gas Tank Pressure
Post by: maxtog on March 09, 2013, 02:09:27 PM
It is normal.
Title: Re: Gas Tank Pressure
Post by: ZG on March 09, 2013, 02:36:18 PM
Normal... mine does it too.
Title: Re: Gas Tank Pressure
Post by: VirginiaJim on March 09, 2013, 03:18:58 PM
I don't think mine does it.  My C10 did it, though.
Title: Re: Gas Tank Pressure
Post by: B.D.F. on March 09, 2013, 03:44:38 PM
Yep, perfectly normal.

By the way, if it makes that noise after the bike has been ridden some distance, it is a partial vacuum and not pressure inside the tank- the tank is sucking IN air, not releasing it. After the fuel tank has been filled with fuel, and the bike ridden any significant distance, the fuel is used up and the volume inside the fuel tank would be (and is) at negative pressure. If the tank was not vented it would crush inward due to the vacuum created by the pumping out of the fuel, not bulge outward due to internal pressure. Google 'crushed motorcycle fuel tanks' and look at the photos of European bikes that have had fuel tank valve failures and you will note that they are all crushed inward, not bulged outward.

Brian

Quote from: thundermax on March 09, 2013, 11:37:35 AM
When I park my 2009 in the garage after riding, I hear a hissing/air releasing sound from the gas tank that goes on slowly until all the pressure is released. Guess it builds up pressure during riding. Don't know anything about check valves or purge valves with the fuel system, but I read the only release area is the gas cap. So there is maybe a vent hole in it? If so maybe mine is blocked with dirty or something?

Does anyone else have this sound after parking?

Any other comments about venting and my situation would be helpful. Thanks.
Title: Re: Gas Tank Pressure
Post by: mvjr1904 on March 09, 2013, 08:10:20 PM
Wait...... Is my bike passing gas?  I only feed it premium?!?
Title: Re: Gas Tank Pressure
Post by: maxtog on March 09, 2013, 09:13:33 PM
Quote from: mvjr1904 on March 09, 2013, 08:10:20 PM
Wait...... Is my bike passing gas?

Nope, it sucks
Title: Re: Gas Tank Pressure
Post by: kwakrider on March 11, 2013, 01:18:49 AM
Quote from: maxtog on March 09, 2013, 09:13:33 PM
Nope, it sucks

 :rotflmao:
Title: Re: Gas Tank Pressure
Post by: dras on March 12, 2013, 10:44:30 AM
Mine will do this too if the bike has been ridden and then filled up on the way home. When I park it in the garage it will start hissing after a few minutes. Pretty sure it's pressurized by the heat coming up off the engine making the fuel / vapors expand. It's less than a mile from the gas station to my house so not drawing much fuel out in that distance.