Stelvio Evap System

[mach1mustang351]

Hey everyone. I have a Stelvio I keep in the lower 48 so I can use it when I go visit. It has an evil issue, every time I run a few gallons of fuel through it, it will build a vacuum in the tank. If I go about 180 miles or more without stopping, it can almost be too much to open the fuell filler again. I am 3400 miles away from the bike, but if anyone has experienced this, I will have a half day before I start my next trip in a few weeks.

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Can you tell us what year the bike is?

On my '09, I removed all the hoses and the charcoal canister and simply vented the tank down to the ground like the old days. A bigger job on mine as it involved removing body work to gain access to the hoses. On the big tank models,  I'm not sure how much of a job it might be. In my case, the canister is/was located under the dash up front. I **assume** it is still in the same location. The real issue is that you have a pinched vent line, plugged valve in the vent line, or the valve is tipped, keeping it from breathing properly.  Simply cuttitng the hoses by the can, may not relieve the trouble.

John Henry

[KraZ440]

This post might help: http://wildguzzi.com/forum/index.php?topic=61878.0

[mach1mustang351]

Sorry to leave out the year... it is a 2014

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Then we are talking about the big tank version. I cannot speak to the location of things there but if you can locate the check valves in the vent system, you can replace them with something like this:

https://www.grainger.com/product/6AFL9&AL!2966!3!166588699612!!!g!81957110414!?gclid=CjsKDwjw0cXIBRCxjqnE3K3sHhIkAL1LezSHz5xX16hRdoEvK7d_2i70iQzOur4TtJ7YKTKyoMKGGgJETPD_BwE&s_kwcid=AL!2966!3!166588699612!!!g!81957110414!&ef_id=WM5qCwAAAQI6gQL3:20170509202636:s

Brass barb. these can be had in a variety of sizes from local sources. Auto parts and hardware stores. If the valve is the source of the trouble, this will resolve it. If there is a pinched hose someplace, (just as likely), then you will still experience the trouble.

My '09 has two hoses that came from the tank, both had check valves in them back when.

John Henry

[KraZ440]

I was just reminded of a similar problem someone had: http://wildguzzi.com/forum/index.php?topic=88137.0

There should be a vent for the tank that is separate from the EVAP system. In at least one case, this vent hole was blocked. The thread above may not exactly match your problem, but it provides some useful thoughts about the diagnosing the problem

[mach1mustang351]

Awesome info everyone. I can't wait to meet up with the bike in 3 weeks and get it sorted. I think between the two threads as references, I should be covered.