I’m changing out the carb, hoses, filter, petcock and air filter on my 2002 TW. I have a fuel leak on the carb and petcock and It’s been 10 years since I installed the hoses so it’s time. My question is there is a hose coming from the rubber boot between the carb and the intake on the engine. The hose runs up under the fuel tank almost to the handlebars and then it has a plug in it. Should it have some type of a breathable one way filter? The bike runs fine so I should probably not worry about it but I am curious. Thanks.