Wildguzzi.com

General Category => General Discussion => Topic started by: Bonaventure on November 28, 2017, 04:26:33 PM

Title: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: Bonaventure on November 28, 2017, 04:26:33 PM
Sounds like a fog horn waaaaay off in the distance and very faint, I guess it's the fuel pump pressure equalizing?  It has to do with the engine radiating heat up and around the tank and causing a temperature induced change in vapor pressure inside, is my guess.   It will sit and do this until it cools down.  Rate of about, I don't know, maybe 1 per minute.  Duration maybe 2 or 3 seconds.  Certainly adds some personality to the beast !!
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: Lcarlson on November 28, 2017, 04:29:46 PM
Mine does it too. Apparently very common for Guzzis.
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: kingoffleece on November 28, 2017, 07:46:07 PM
Tank pressure venting.
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: AH Fan on November 28, 2017, 10:25:35 PM
Yup .............. pressure relief.
All my 8Vs do it to a degree but not so for the others?

Ciao
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: Rhodan on November 28, 2017, 10:45:30 PM
My V7 does it too.
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: Bulldog9 on November 28, 2017, 11:31:51 PM
It's the fuel evap system. There are several threads on how to eliminate the charcoal canister and check valve contraption. I removed mine on the Norge & Griso. Jury is out on any performance gains. I noticed an immediate change in a more stable idle, and maybe a small improvement in throttle response, but not much.  Of course now the fuel tank vents to atmosphere.
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: JeffOlson on November 29, 2017, 01:29:36 AM
^  I did the same with my Norge. No more groaning, at least not from the bike!
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: ohiorider on November 29, 2017, 03:42:37 AM
From a B1100 manual.  Examples of Euro vs USA tank venting.


(http://thumb.ibb.co/bzzh5G/Slide1.jpg) (http://ibb.co/bzzh5G)

Euro venting to atmosphere


(http://thumb.ibb.co/iJ1Jeb/Slide2.jpg) (http://ibb.co/iJ1Jeb)

USA venting thru carbon canister.
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: Bonaventure on November 29, 2017, 06:12:48 AM
As long as the canister system is working right, I'll probably keep it intact.   :cool:
Title: Re: Stelvio 8V Groaning Sound in Fuel Tank When Parked After Ride
Post by: JeffOlson on November 29, 2017, 12:59:45 PM
The charcoal canister on a former BMW 7 Series went bad from gas pump jockeys over-filling the tank. (In nanny-state Oregon, we are not allowed to fill our own automobile gas tanks.) It cost nearly $1,000 to replace it. Fortunately, Kuni BMW took care of it for me. Just a cautionary tale about charcoal canisters...