Knob on fuel tank?

[Bob & Peggy Standeford]

I have #516, 1999 with a silver looking fuel tank, on the top right is the filler hole and on the top left is a black knob. What in the world is it for? It will turn, but I'm afraid to pull on it or do anything with it till I find out what it's for. Thanks for the help.

[Chester B. Stone, Jr.]

The knob is a primer pump in case the engine runs out of fuel. Sorry, but I know it pulls out but I have never used it.