I had been feeling some surging on hard acceleration and highway speeds. A few times I ran out of gas and would have to switch to reserve early. Then at fill up it would only take about 3-1/2 gallons.
I did suspect the venting, because I've read stories of guys blowing out the vent lines.
Other than that I didn't have a specific reason to suspect the smog equipment. The side covers and seat were off the bike and as I was looking it all over, I decided to go for it, figured it would be easy to undo if it made the bike run poorly.
At the time I didn't check the canister for gas, whet out and check it just now, no gas present.