To Cap( the fuel regulator) ... or not?

[Tom in Virginia]

'02 V11 LeMans, all original, no mods.  Bone stock collector bike with 2400 miles when I purchased last summer. 

Question: I noticed on the right side of fuel tank an open ended tube.  Not sure what is going on here.  The '03 LeMans has entirely different fuel delivery setup.  Should I vacuum cap this open ended tube or is it a vent to atmosphere??  Thanks in advance. 

 

[Lucky Phil]

13 minutes ago, Tom in Virginia said:

'02 V11 LeMans, all original, no mods.  Bone stock collector bike with 2400 miles when I purchased last summer. 

Question: I noticed on the right side of fuel tank an open ended tube.  Not sure what is going on here.  The '03 LeMans has entirely different fuel delivery setup.  Should I vacuum cap this open ended tube or is it a vent to atmosphere??  Thanks in advance. 

 

Under no circumstances cap that port off. The fuel map is designed to meter fuel at a pressure dictated by the regulator which controls that pressure via a bladder with spring pressure on one side and atmospheric pressure on the other. Plugging the vent will seal the bladder from atmospheric pressure and affect the delivery pressure. It was originally used on other applications to regulate fuel pressure to inlet pressure but everyone abandoned the idea early in the piece. The very first injected ducati 851's used it but then discarded the connection.

Ciao

 

[docc]

+1 with Lucky Phil.

[Tom in Virginia]

 Thanks Lucky Phil.  Really appreciate your quick response.