Aftermarket tank. Petcock issue
 

Bought a bobber pacifica tank on amazon.the original tank has 2 fuel lines coming out of it going to the carburetor. What are they, more specifically, what's the smaller line. Does anyone know what kind of smaller aftermarket tank might fit the specs. I can't find the specs anywhere. It's seems like I'm in a deadzone with the 2006 as far as owners manuals. This is my second set of parts I have to return after everything originally looked okay specs wise.

So the way the petcock on these bikes works is via a vacuum generated by the carburetor. The carb pulls vacuum on the diaphragm inside the petcock which allows a free flow of fuel. When you turn the petcock to "PRI" it bypasses the diaphragm. That's why you'll see people talking about "rebuilding" the petcocks on these bikes because that mechanism wears out or the diaphragm gets a hole and remains closed.

TL;DR - The larger line at the bottom of the petcock is the fuel line proper and the small rubber tube on the back of the petcock is the vacuum line. Can you not fit the original petcock on the new tank?

If you run a single line petcock, make sure to plug that vacuum port on the carb.

Also, when needing help with part diagrams, part numbers, etc. I always recommend partzilla.

https://www.partzilla.com/catalog/su...z250/fuel-cock

Ditto on Partzilla. They not only have good parts diagrams, but usually have OEM parts in stock. They can be a little pricey, but if you need it, you need it.

Thank you for your help! I've only ever run with a single line before. Didn't know about the vacuum line. It's cool learning new stuff.