[Back2-2]

Looks like the "R" & "X" are different.
My "X" has a O-ring that goes around the handle that seals it. That lets the disc just take care off sealing each port from one another.

[JimDirt]

I have to run to town tomorrow (i live 10+ miles from town) , so i will go to my Storage and get my stock 450X tank , i am pretty sure it still has a petcock and fuel lines on it because i have both bikes with stock and IMS tanks , so they should both be set up ready to install

So i will bring it home and pull it apart and see if it has a O-Ring , but i remember changing the diffuser a while back because it leaked (at that time i was able to get a replacement from the bike shop *the K&L kit i spoke of before*) , it could be the X has a O-Ring because of Reserve