Spark plug gap? Evinrude 72 50hp Lark, 50273C

[kippstakes]

As I do research, I'm getting mixed signals on the proper plug gap for this model. I'm running QL77JC4s, and have read that both .03 and .04 are correct. I've also read that .03 generally applies to later models and .04 for earlier Evinrudes, like my 72. However, I have encountered the .03 opinion more often, and applied to all years.

Can anyone clarify?

Thanks

 

[Vic.S]

Re: Spark plug gap? Evinrude 72 50hp Lark, 50273C

As I do research, I'm getting mixed signals on the proper plug gap for this model. I'm running QL77JC4s, and have read that both .03 and .04 are correct. I've also read that .03 generally applies to later models and .04 for earlier Evinrudes, like my 72. However, I have encountered the .03 opinion more often, and applied to all years.

Can anyone clarify?

Thanks

Originally I think you will find that the specified gap was 0.040".

Sometime in the late 1980s a service bulletin was issued revising most, if not all, plug gaps to 0.030".

0.030" is the currently recommended gap for your engine

Not sure of the reason but I believe it was because lower voltages then developed place less stress on ignition components.

 

[kippstakes]

Re: Spark plug gap? Evinrude 72 50hp Lark, 50273C

Perfect. Thank you.