Cali bike?
 

I think the Duc I bought may be a California bike. It has a fuel vapor recovery can and hoses routed to the intakes and the fuel tank. Other than having all that junk hanging off the side of the frame I guess it does no harm, or does it? Does anyone know if removing said stuff and just venting the tank normally and plugging the intakes would upset the tuning?

The evap/charcoal stuff doesn't do any harm, I don't know why people bother removing it.

Now, if it has one of those air injection systems into the exhaust to burn unused fuel, then that can interfere with getting a power commander set right.