Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Hi, my name is***** will be assisting you.
The check valve allows air to be pulled into the fuel tank but will not allow fuel to come out of the tank. It is in place in order to keep from developing a vacuum inside the fuel tank which would cause you to no longer be able to pull fuel from the tank to the carburetor. There is no specific position for the check valve other than it needs to be outside of the tank and in a position that it does not get hit or knock off easily.