Belly tank info

[valkcan]

Hi guys
I have been lurking around here ever since I sold my Goldwing and purchased a Valk in 09 of this year. Winter is coming my way fast and I have a few projects in mind.
I have been reading a lot about the belly tanks and since I work in a sheet metal factory and, I don't have $500.00 to shell out on a ready made one, I will give it a go and design and fabricate my own.
I do have 1 question before I start this: Why do we need to modify the original tank and braze a bung in it? Would the standard petcock converted to manual not flow the fuel in the belly tank? I am just intrigued by the why of this mod and is it really necessary. BTW, I have the cobra exhaust and just want to be abel to run approximatly the same distance on a tank than I did with my GL1500.
Don

[Bone]

Here is a link to the belly tank site http://www.rmworksinc.com/Information.html

I'm guessing they will tell you why.

[tank_post142]

the original petcock/fuel line are used as a vent for the belly tank.fuel is fed down the 1/2 line into the belly tank and displaced air is vented into the tank via the original fuel line, then it works in reverse when the reserve is used.

[valkcan]

Got it. Thanks
Don