Removed the carbon evap canister on the Super Duke today, gained a whole bunch of space under the seat...
It had two hoses, one is a gas tank vent and has to be left open, I routed it down by the rear cylinder and out the bottom with another hose. It's the small hose on top of the frame.
The second hose runs to a valve on the front of the airbox, then tees off and goes to a nipple on the side of each cylinder head. I just removed the single hose from the canister to the valve and plugged the valve nipple, the other tee hose going to the cylinders can be removed and capped as well, but it will take removing the airbox to access the front cylinder. I'll wait until the SAS removal plates come in off back order and do it all at once.
The gas tank pivots on two bolts at the rear, removing a single bolt in front allows you to lift it up to access the airbox. Several threads on the Super Duke forum warned that it's a bitch to get the gas tank bolt lined up again and you have to remove the pivot bolts as the plastic tank tends to expand, especially when full of gas which mine was. Sure enough the mounting tab on the tank was way off from lining up with the frame, but it seemed like undoing the pivot bolts was only going to complicate matters worse. I took a large flat screwdriver, wrapped the tip in tape, inserted it between the front of the tank tab and the top triple and gently pried until the bolt dropped into place.
It had virtually no underseat space before, registration slip was all that fit. Can fit a towel, small chamois, kickstand pad, helmet cable lock, and even the tool kit if I want.
Makes zero difference in how the bike runs, the tank just vents to the atmosphere now instead of back through the airbox. Hopefully the SAS kit (think PAIRS plates) will be here soon, can get rid of the rest of the plumbing. Also ordered 02 sensor eliminators, let you unplug the sensors without tripping the light. Supposed to eliminate the low throttle snatchiness, which does make the bike a handful in low speed corners and around town, easy to lurch forward when you're only trying to apply a little throttle.