Spark Plug Gap Setting

[Algielong32]

1984 Johnson 140hp V4. I need to know the gap setting or should I use the bullseye marine plug? Which Is Better?

 

[WillyBWright]

Re: Spark Plug Gap Setting

.040 and what is a bullseye marine plug?

edit: Oh, you mean a surface gap. Those are best for sustained high speed operation. Conventional plugs are better for all-around and low speed operation.

 

[OBJ]

Re: Spark Plug Gap Setting

I believe that the recommended plug is a Champion UL77V....which is a surface gap.

At any rate, use only the recommended plug.

 

[rickdb1boat]

Re: Spark Plug Gap Setting

http://www.boatsetup.com/SparkPlugChart.pdf

 

[Algielong32]

Re: Spark Plug Gap Setting

Thank you.

 

[Walker]

Re: Spark Plug Gap Setting

I know a lot of people on this board recommend .040 gap, but I've always gotten better performance on the V4 crossflows throughout the throttle range gapped at .032