johnson 50HP spark plug question...

[craigmpak]

trying to find the proper spark plug for an 89 Johnson 50HP
(model CJ50becec) ...

existing plug is a QL78C

went to reference the year/model at an auto store/marine and they are giving me a QL78YC (or was it QL78CY) ... anyways there was a Y in it and it was quite a bit longer ....

i have a johnson repair manual and they're asking for a L77JC4


so which freaking plug is it????????

 

[tashasdaddy]

Re: johnson 50HP spark plug question...

i've had better luck with QL77JC4 gapped at .030. here is the chart.
http://www.boatsetup.com/SparkPlugChart.pdf

 

[craigmpak]

Re: johnson 50HP spark plug question...

thanks a million.......