Stupid Spark Plug Question

[scampbell]

I have an '84 Evenrude 150. I just went to BOW to get a new set of plugs. They have an NGK plug listed for this engine. The stupid part is...these plugs do not have a gap. They are smooth on the end, no "L" piece that creates the gap. How do these work? I know I am old fashion, but I just cannot understand how these function.<br /><br />Are these better than conventional plugs?

 

[Barnacle_Bill]

Re: Stupid Spark Plug Question

They work just fine. Especially if most of your running is at high speeds. They spark between the center electrode and the base. If your are going to use the motor for trolling, you might want to go to a conventional plug like Champion L77JC4. I think that is the correct no.

 

[DHPMARINE]

Re: Stupid Spark Plug Question

Every plug manufacturer will list a plug they make to fit your motor.<br /><br />for Jonnyrudes,stick with Champs.Generally gappaple ones.There is one,QL16V I think,for some applications.It is a surface gap.But not cheap.<br /><br />Get the original plug,or what OMC/BRP recomends,not what WQFG plug maker says will work.<br /><br />DHP

 

[scampbell]

Re: Stupid Spark Plug Question

Thanks. One more question. This motor seems to run rich. I've been told that I may want to try a hotter plug. How do you determine if one plug is hotter than another?

 

[DHPMARINE]

Re: Stupid Spark Plug Question

motor seems to run rich?How so and what is the motor doing wrong?<br /><br />Each plug manufacturer has a chart showing cold to hot plugs that they make.<br /><br />Each motor manufacturer recommends a plug to use.<br /><br />Whose chart do you want to use?<br /><br />DHP