Go here to look up the part number according to your motor's model: Johnson Evinrude Outboard Motor Parts by Year 1955 to 2011
Call Tim's outboard 218-682-2331 w/part number.. they may gave a good/used. Or look here for used: http://forums.iboats.com/johnson-evinrude-outboards/salvage-yards-wilde1-438822.html
Or call any J/E dealer w/part number and inquire about a new one (Tim's will be able to get a new one too.. if available).
Good luck!