champion or ngk spark plugs

capitan

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For a 1995 Johnson 8hp two stroke would you fit champion or ngk plugs into it and which ones would you recommend please?
 

Vic.S

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Re: champion or ngk spark plugs

The current recommendation is for Champion QL77JC4 or QL86C gapped at 0.030" (thats 0.7 to 0.8 mm you and me) QL86C are just a little hotter and may be useful for a lot of slow speed running otherwise QL77JC4 are the preferred option

The official line is only to use Champion plugs!

In the UK NGK perhaps a little more common and easier to source.

If you use NGK then the equivalent BZ7HS-10, although these are supplied gapped at 1.0mm

With OMC CD ignition it is important not to use resistor plugs such a BR7HS

the Q in the Champion number and Z in the NGK number indicates low resistance, or inductive, suppression.

BR7HS is NOT equivalent to QL77JC4 no matter what your dealer may try to tell you.

If you must use NGK its BZ7HS-10, although unsuppressed Champion L77JC4 or NGK B7HS will work satisfactorily if you are not worried about the radio interference they may cause
 

capitan

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Re: champion or ngk spark plugs

Thanks Vic.S So would you say Champion Ql77jc4 and NGK bz7hs-10 are the same. The reason i am asking is our local motor factors have said they used to sell Champion spark plugs but they had so many returned that they completely removed the Champions and now stock/favour the NGK's. What are your thoughts please?
 

Vic.S

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Re: champion or ngk spark plugs

BZ7HS ( or BZ7HS-10) are the nearest NGK equivalent to QL77JC4

I'd use then happily ( in fact i have a set of NGKs as well as the original Champions for my 6hp Evinrude .. . although they are the plain old non-suppressed B7HS. I cannot tell any difference .

Most of the world prefers NGK plugs but as I said the official line is that only Champions are now recommended for OMC engines and folks on this forum will support that.

I suspect the problem has been that the Champion Q series plugs were developed specially for the OMC CD ignition and for a long time there was no NGK equivalnet. As a result the NGK resistor plugs were supplied in their place. You still find them on some lists but the OMC CD system does not like them.

I also wonder if there was some commercial deal between OMC and Champion. I always seems odd that only Champion plugs are now recommended for older ( pre CDI) engines for which AC or Autolite plugs were listed as alternatives when they were first supplied :(

I am not surprised about bad experiences with Champions. I had a car many years ago that was a bit particular about its plugs and the motor club at work got bad batch. I think after I had retuned the second set to them they sent the whole boxful back. But it's an isolated incident AFAIK

Just don't use the resistor plugs. Use the unsuppressed B7HS if you cannot get the BZ ones.

All the above purely my views.
 

Tim Frank

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Re: champion or ngk spark plugs

I never try to cross-match plugs from one brand to another...mainly because you can never be sure who has done the "testing" other than being fairly sure it is not the plug mfrs themselves....and they are never identical matches.

I only use plugs recommended by the owner's manual or by the plug manufacturer themselves, for a specific application.

NGK recommends for both my 6hp AND 8hp Evinrude BR6HS plugs...which seem to work almost as well as the Champions....for me.


But as Vic said :
All the above purely my views.

^^^^ goes for me, too....;) If it works, keep doing it!
 

Vic.S

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Re: champion or ngk spark plugs

NGK recommends for both my 6hp AND 8hp Evinrude BR6HS plugs...which seem to work almost as well as the Champions

NGK grade 6 plugs are in fact hotter plugs. Probably about equal to a Champion grade 8. That's fine if you need hotter plugs.

However if have OMC CD ignition you should use the BZ plugs instead of BR. They will work as well as Champion "Q" series not "almost as well"

Older engines with points ignition can of course use resistor plugs.

A full technical explanation of the need for inductive suppression rather than resistive suppression can be found at http://members.iinet.net.au/~pauldawson/iame26-spark-plugs.PDF
 

Tim Frank

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Re: champion or ngk spark plugs

NGK grade 6 plugs are in fact hotter plugs. Probably about equal to a Champion grade 8. That's fine if you need hotter plugs.

However if have OMC CD ignition you should use the BZ plugs instead of BR. They will work as well as Champion "Q" series not "almost as well"

Older engines with points ignition can of course use resistor plugs.

A full technical explanation of the need for inductive suppression rather than resistive suppression can be found at http://members.iinet.net.au/~pauldawson/iame26-spark-plugs.PDF

Sorry, I would call that link (URL begins with "members....." :eek:) a technical OPINION not a technical explanation, and I would give it less credibility than NGK's expertise.
I have dealt with NGK's Technical Ceramics Division when purchasing components for a high tech company, and their expertise is impressive to say the least.


NGK specifies to use the BR6HS for my motors, and that is good enough for me.
 

Vic.S

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Re: champion or ngk spark plugs

Sorry, I would call that link (URL begins with "members....." ) a technical OPINION not a technical explanation
The article in my link, which is a direct link to the article on the author's own website hence the URL, is one of a series, mostly but not exclusively, on outboard engine technology written for the (Australian) Instutute of Automotive Mechanical Engineers (IAME) member magazine - ?The Automotive Engineer?.

I apologise for not prevously stating the source of the article.

The facts are that OMC recommended only the Champion Q series plugs with all their engines with CDI.
Q series plugs are low resistance inductively suppressed plugs.
Only the Z series from NGK are inductively suppressed.

NGK plugs have bad reputation when used in Johnson and Evinrude outboards which I suspect is not because there is anything wrong with NGK plugs, au contraire, but because in the absence of inductively suppressed NGK plugs until relatively recently, resistor plugs were recommended and used with sometimes disappointing results.

The hard line approach would be to respond to all questions about plugs by saying use only the engine manufacturers recommended plugs! In the case in point this amounts to QL77JC4 or QL78YC.
I prefer the softer approach, particularly with questions originating in the UK where Champion plugs are not so readily available, namely to suggest the nearest equivalent NGK plug. In this case BZ7HS-10.

You dismiss the article in my link as an "opinion" rather than a techincal "exlanation" I, therefore, look forward to reading your explanation for the reasons OMC recommended only inductively suppressed plugs for use with their CD ignition systems.
 

Tim Frank

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Re: champion or ngk spark plugs

I prefer the softer approach, particularly with questions originating in the UK where Champion plugs are not so readily available, namely to suggest the nearest equivalent NGK plug. In this case BZ7HS-10.

You dismiss the article in my link as an "opinion" rather than a techincal "exlanation" I, therefore, look forward to reading your explanation for the reasons OMC recommended only inductively suppressed plugs for use with their CD ignition systems.

I'm not "dismissing" anything....including any of your stated opinions.

But to be pragmatic, I own two Evinrude O/B which require Spark Plugs.
The Manufacturer of those outboards has specified a specific Champion Spark plug....and NGK...a leading manufacturer of spark plugs has specifies one of their plugs as being acceptable for these motors.

Sorry, but I will be following(and have with good results) those guidelines rather than your well-intentioned advice, which is different from NGK's.

If these work for you, that's great, but the equivalency that you state is not supported by either OMC or NGK ....which is.... BR6HS

Intuitively, picking a spark plug for a small outboard motor should not require internet research and deep analysis; you may be over thinking all of this.
 

Tim Frank

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Re: champion or ngk spark plugs

Maybe these 2 links will help the discussion. They both explain the recommended use of suppressor style sparkplugs in the J-E CD ignition outboards. One by NGK and the other by Champion.


http://www.ngk.com/glossary.asp?kw=Resistor&manID=1&pt=1

http://www.championsparkplugs.com/sparkplug411.asp?kw=Resistor&mfid=2

Neither of those links are actual spark plug manufacturer, they are actually both links to the same on-line retailer, and there is a wealth of conflicting information there.

This is a link to NGK:
http://www.ngksparkplugs.com/part_finder/index.asp?mode=nml
 

Tim Frank

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Re: champion or ngk spark plugs

For a 1995 Johnson 8hp two stroke would you fit champion or ngk plugs into it and which ones would you recommend please?

Sorry, your thread is getting diverted off course with a fair amount of opinions that weren't really exactly what you asked.

Straight answer to your question :

My recs:

1) OMC specs QL77JC4, which I use in my '94 8HP 2 - stroke with good results.
That is usually an easy plug to get around here, so no problem 90% of the time.

2) Occasionally I use NGK for availability or convenience. I go with the application spec from NGK themselves which for this motor is BR6HS.

Works for me, so that is as deep as I am inclined to dig.
 

Faztbullet

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Re: champion or ngk spark plugs

All my customers I service(outboard & I/O's) get NGK plugs and have never had a problem with them(I also use correct series). I have used NGK's since the late 80's and you get a bad/weak one every now and then. I also know of a OEM dealership that swears by Denso's and Autolites!!!
 

Tim Frank

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Re: champion or ngk spark plugs

All my customers I service(outboard & I/O's) get NGK plugs and have never had a problem with them(I also use correct series). I have used NGK's since the late 80's and you get a bad/weak one every now and then. I also know of a OEM dealership that swears by Denso's and Autolites!!!

Don't think anyone is dissing NGK....certainly not me.

The question was asked about which is the correct plug for a specific motor....and what should be a dead-cert is far less than that.

Way too much conflicting info out there for our collective good....;):eek:

For interest's sake since you are a pro, how do you decide what the correct NGK plug is? Who do you trust?
 

bignefan

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Re: champion or ngk spark plugs

Wow, you guys are great.I would say with an 8 horse I would buy one of each and try them out and see for myself the result.Now on the other hand I have twin 175s thats 12 plugs I'll stick with the book and see how they burn
 

Tim Frank

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Re: champion or ngk spark plugs

Wow, you guys are great.I would say with an 8 horse I would buy one of each and try them out and see for myself the result.Now on the other hand I have twin 175s thats 12 plugs I'll stick with the book and see how they burn

That certainly changes my " I get change from a $10- when I buy plugs" to an "ouch"...:eek::D
 

Faztbullet

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Re: champion or ngk spark plugs

How do you decide what the correct NGK plug is? Who do you trust?

I use the NGK sparkplug book and Quicksilver product guide.
 
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