What plug do I use?

[abesz]

Just accidently deleted a post of mine stating the same question, but whats the best plug to use in 1985 Evinrude 150?

 

[Joe Reeves]

Re: What plug do I use?

Champion QL77JC4, gapped at either .030 or .040. Gap of .040 was the original recommended gap (starting in 1973 or so), changed to .030 at some point in the 1990s.

 

[ezeke]

Re: What plug do I use?

The original listed plugs and the currently recommended plugs for your specific motor are the Champion UL77V and/or QUL77V. The L16V is the alternate.

http://continuouswave.com/whaler/reference/BRP/SparkPlugChart2008.pdf

 

[abesz]

Re: What plug do I use?

Between the standard and the resistor type, is there a primary difference why I should use one instead of the other (besides its listed for the resistor type)? Also, what does the 'Q' stand for?

 

[ezeke]

Re: What plug do I use?

Q plugs suppress radio interference that causes problems with electonic equipment.

 

[abesz]

Re: What plug do I use?

Okay, thanks. Another question, I heard the resistor type plug seems to foul more at idle but better at high speed. I read thats the reason people are diverting away from the listed plug to the QL77JC4. Would I have to worry about any possible damage if I would use that over the UL77V?

 

[ezeke]

Re: What plug do I use?

You have to choose between what is and has been recommended by OMC/BRP during the life of your particular motor and what others may find will work. That is entirely up to you.

 

[Joe Reeves]

Re: What plug do I use?

Both type (surface gap and electrode) are the recommended plugs. Neither will cause damage. The surface gap plugs have no heat range to speak of and are quite prone to fouling. Personally I prefer the electrode plug (QL77JC4).