Discrepancy in champion plug

[yoster]

Hello,

Getting ready to replace the plugs in my BE115GLEUA.

Quick question, the original engine manual says to use Champion QL82YC, while the OEM shop manual that you guys recommend I pick up says to use QL78YC. So... which one is correct?

The previous owner used NGK BPR7HS plugs, which actually have worked extremely well in the 3 times I've ran it since purchasing. No issues at all. Should I just replace it with those same ones?

 

[tashasdaddy]

Re: Discrepancy in champion plug

latest info: http://www.docstoc.com/docs/4877037/Spark-Plug-Application-Chart-for-Evinrude-Johnson-Outboards-thru

 

[Vic.S]

Re: Discrepancy in champion plug

Take note of the information in TD's link

Also note that you should be using inductively suppressed plugs (Champion "Q" series) Not the resistor plugs you have in at the moment. ( R in the number = resistor)

Two reasons

The resistor plugs are not suitable for OMC CD ignition systems. The inductive plugs have been developed for this application. The technical explanation is HERE

Secondly the inductively suppressed plugs are recommended for all engines with VRO or OMS systems ( note 3 in TD's link)

There is no exact NGK equivalent of QL78YC or QL82C but the equivalent of QL77JC4 is BZ7HS or BZ7HS-10 . The "Z" denotes inductive suppression and the -10 merely that they are supplied gapped at 1mm ( 0.040")

In short Champion "Q" plugs or NGK "Z" plugs but not "R" plugs!

Officially only Champion plugs are recommended.

 

[Dhadley]

Re: Discrepancy in champion plug

Those motors are pretty sensative to combustion temps and rarely like NGK plugs. A lot depends on what fuel you're using but we like to stay with the cooler QL77JC4s and we're not big fans of the extended reach on recreational motors. Especially if the motor is even close to being lugged.

 

[yoster]

Re: Discrepancy in champion plug

Thanks guys! Great help. I though the NGK's would be ok since other boat online stores had them listed as an "alternate plug," however it's clear that that isn't the case! Also thanks for the link to the plug info - I actually had that one but didn't know if it overruled the owners manual, which it sounds like it definitely does. I'll be going with the QL78YC plugs.