Spark plug question

[talon359]

I have a 1997 Johnson 15 hp motor, I have been using champion spark plug # QL82C in it. I was lookin at the parts manual at shop evinrude and it showed to us QL77JC4. Does anyone know the proper plug? Thanks

 

[HighTrim]

Re: Spark plug question

What is the model number of your outboard? Is it commercial, 4 stroke, big bore, etc...?

 

[talon359]

Re: Spark plug question

Sorry, model # is J15REUC

 

[talon359]

Re: Spark plug question

^^^

 

[HighTrim]

Re: Spark plug question

You have the correct plugs in there, although the JC4's are also listed on the www.shop.evinrude.com site, as well as a couple others.

I think the JC4's were used from '77 to '92, then the QL82C's from '93 to '01. This is for the 2 stroke non commercial motors of course.

The QL82C's are a higher heat range plug.

 

[Okee Jimmy]

Re: Spark plug question

The omc parts book lists several sparkplugs that can be used in your motor.

standard plug is:
0437684 QL82C

optional plugs:
0386941 L77JC4
0433627 L16V
0387623 QL77JC4
0432424 QL16V

 

[wbeaton]

Re: Spark plug question

Both are fine. The 82 is hotter, which is better for trolling.

 

[Vic.S]

Re: Spark plug question

For anyone who likes technical explanations of things see THIS.

Towards the end it explains why plugs with low-resistance high-inductive suppressors should be used with CD ignition systems. They are the plugs denoted by the letter Q (or Z for NGK plugs)

 

[talon359]

Re: Spark plug question

What would the proper spark plug gap be? Thanks

 

[HighTrim]

Re: Spark plug question

.030

 

[MikDee]

Re: Spark plug question

For anyone who likes technical explanations of things see THIS.

Towards the end it explains why plugs with low-resistance high-inductive suppressors should be used with CD ignition systems. They are the plugs denoted by the letter Q (or Z for NGK plugs)

On a point, not to hijack this thread, but being as you brought this up, I am in TOTAL AGREEMENT with your statement, and the info in this link, BUT, WHY, do all Force outboards (including my 89'-125hp) Use a Non-Resistor spark plug (UL18V) On what I believe is a CD ignition system??? IMO, it stresses the ignition system, and just creates problems!

http://www.championsparkplugs.com/more_info.asp?otherMotiveID=12338&pid=4430