It is. It's a pressure relief line from the tank. If you look at it on a hot day you'll see a "haze" of gas vapors coming out.Welcome bud. I'm in California and the bikes here have to have evap storage canisters. On my Stryker that hose comes from the fuel tank into said canister. Also on my Stryker The coolant over flow tube is just in front of the rear tire through the framework. My guess is that it's a downdraft tube for the fuel tank.