I have an older Evenrude 6 hp I think it is 1974<br />Model # 6904 F<br />Serial # J0003089<br />My question well I have 2 first is this a 1974?<br />And second do I gap the plugs @ 0.30?<br />I just changed my plugs and now it will not crank I am using NGK B6S.<br />Thanks for any tips you may...