If I am not mistaken the ETECH models were computerized? If mechanical you will see a cover on top of the fuel pump. One bolt hole should have a plug or a funny looking bolt head on it that requires a special socket. (if the socket is unavailable to you you could always weld a nut on it and put a normal bolt back in its spot.) There should be two screws inside there on top, one for air and one for fuel. Screw them in, and if your anything like me you would put them all the way haha. A good working pyrometer is highly recommended after doing this.