Mines still on there. With the current price of gas, I'm burning fumes and all.
There are 2 vent valves in the system. One is electrically controlled and vents the float bowls when the ignition is on. The other is vacuum controlled and connects the canister purge line to the carburettors when the engine is running.
There is also a rollover valve in the 49 state version (no vapor recovery) in the tank vent line that keeps gas from draining from the tank if the bike falls over. There is a one way (in) valve in the gas cap to keep the tank from building a vacuum while riding, but closes under pressure so expanding gas won't spill out on the tank. The rollover valve seems to also allow pressurized air out of the tank, but closes under the weight of liquid gas coming down the hose.
