Can anyone help me out with what the plug gap should be for a '78 55hp Johnson mod. 55EL78, and for a '73 6hp Evinrude mod. 6302S.<br /><br />Thanks<br /><br />Sean
0.030" for one.<br />0.030" for the other.<br /><br />You have to guess which is which. <br />You can also experiment with slightly larger gaps, up to about 0.040" to improve idle. It may harm your midrange and top-end though.<br /> OMC Spark Plug Chart
<br />You can also experiment with slightly larger gaps, up to about 0.040" to improve idle. It may harm your midrange and top-end though.<br /> OMC Spark Plug Chart
