A jade machete is used to repair the Tai Bwo Wannai gates. It may be obtained by purchasing it from Safta Doc in northern Tai Bwo Wannai Village with items, or from Gabooty's Cooperative store in the village gates for 1200 trading sticks (1000 if you are wearing any tier of the Karamja gloves). You will need to get one from Safta Doc for the Karamja Achievement Diary, so make sure you have begun the diary before you buy this item.