Stock Framed CRF450 Fuel Line Mod.
Getting to the top end of your motor to access the carb, plug or cables is a pain in the butt if you need to do it fast in between race.
The major object in your way is the fuel tank, which actually removes quite easily, but is kind of a pain if its full of fuel. You have to remove the fuel valve and disconnect the hose, or remove the hose, and plug it off, and anyone who's done it will tell you a load of race fuel in your shoe on a hot day is no fun.
