Replaced fuel filler cap and now have a vacuum issue

[doozibrut]

The locking mechanism recently broke on the fuel filler cap on my 2007 ST1300. No biggie - went to Babbittsonline.com and got a new one. Installed it without issue, but now there is a serious vacuum seal when I try to open it. Almost couldn't get it open one time. Even after short rides, it is difficult to open and makes an audible sucking sound when it does open. Any advice?

 

[Kevcules]

Take off the tupperware on the right side, you will see a black charcoal cannister. Check the hoses on that and the fittings on the cannister to see if they are plugged.