NGK plugs

solberg

Cadet
Joined
Aug 30, 2005
Messages
11
Allright, what is the deal with NGK plugs. I have a 1989 40hp Evenrude and am having problems with it. In trying to fix it, I put new plugs in it. The place didn't have Champions but had NGK so they crossreferenced them and I threw them in. Now glancing through this forum, I see NGK is a no no. I just called a local boat shop and they said NGK's are fine. What's up?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: NGK plugs

NGKs tend to be a little hotter than Champions. And theres nothing wrong with NGKs as a spark plug. The OMC motors were calibrated (jetting, timing, port configuration etc) for the Champions. Just like most Yamahas and Mercs are calibrated for NGKs.<br /><br />A hotter plug all by itself may not hurt anything but that coupled with a lugging motor or old fuel or wrong octane or low water pressure or restricted water passages or wrong timing or a slightly restricted fuel supply -- can lead to a damaged piston. <br /><br />Excess combustion heat is the mortal enemy of a 2 stroke carb'd motor. I'd suggest to do everything possible to keep it within the design parameters. <br /><br />Some OMC motors are a little more sensitive to combustion temps than others. Yours is not the most sensitive but it isnt the most forgiving either.<br /><br />Nowhere in any OMC literature do they recommend anything other than Champion for your motor.
 

solberg

Cadet
Joined
Aug 30, 2005
Messages
11
Re: NGK plugs

Thanks for the reply Dhadley. I hate that when there's only one place to get something and they don't have the exact one you want.
 

dajohnson53

Lieutenant Commander
Joined
Apr 28, 2004
Messages
1,627
Re: NGK plugs

Originally posted by solberg:<br /> Thanks for the reply Dhadley. I hate that when there's only one place to get something and they don't have the exact one you want.
Where did you get them and where did you look? I always buy my Champion marine plugs at the autoparts store rather than the boat store. They are much cheaper. Availability is not 100% (but nearly so), so I always call ahead first and can almost always find what I need. I've used NAPA, Carquest and Schucks, so ymmv.
 

midsized johnson

Petty Officer 2nd Class
Joined
Jul 28, 2005
Messages
155
Re: NGK plugs

When I got my Johnson, I put required Champion plugs in. I ran it once, one of the plug's ceramic came loose. Replaced that plug, ran motor again, started losing rpm's got back to dock, #2 plug had exploded and fried plug wire. Bought NGK's no problems since. Now I wonder, should I have purchased the plugs at a auto parts store? I bought them at Boater's World and paid a premium for them. Shouldn't all plugs be created equal? :D
 

BF

Lieutenant
Joined
Apr 8, 2003
Messages
1,489
Re: NGK plugs

Nowhere in any OMC literature do they recommend anything other than Champion for your motor.
Actually in the factory service manual for my '70 25hp they say the plug type is J6V or NGK B8S...<br /><br /> the motor had B7S in it, and idled poorly. But since it was the wrong heat range, and one of the plug caps was falling off, I can't blame it on NGK. I intend to compare new J8S's to new J6C's and see how it likes 'em.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: NGK plugs

Thats why I said for HIS motor (1989 40). But in fact the plug has changed for a 1970 25 hp. The new factory spec is for the Champion J4C. Always go by the latest recomendations. As the fuel changes so does the recomendation.
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: NGK plugs

This crap I hear lately of champion plugs busting is a bunch of crap....<br />We are a large dealer of Briggs, Tec., and Kohler small engines...the 3 largest customers of champion plugs in the world. My dad was an OMC dealer for 20+ years as well. we've never had a champ break that we installed...customer installed plugs break because they don't use the proper tools.<br />Very few people even know how to properly install a champion plug, ...most are left too loose and don't disapate heat as intended...I see this everyday with the small engines AND the outboards.<br />I took in a Johnny 120 Looper yesterday with NGK plugs, and the info I got from the owner of this pontoon was all he could turn was 4800 RPM. I checked the cross on the plugs, found they were not even close to the correct plugs as a cross-over and with further invetigation, found 3 of 4 pistons with a good start at errosion of the piston...the engine is JUNK.<br />To add to this, the only official publication of plugs for OMC/BRP is the most current P&A book.<br />Dhadley knows EXACTLY what he is talking about...follow his advice or have an engine like I had come in yesterday, unless you have an extra 10 grand laying around to cover the mistake of installing the wrong 3 dollar a piece plugs...
 

dajohnson53

Lieutenant Commander
Joined
Apr 28, 2004
Messages
1,627
Re: NGK plugs

Originally posted by Mid-size Johnson:<br /> When I got my Johnson, I put required Champion plugs in. I ran it once, one of the plug's ceramic came loose. Replaced that plug, ran motor again, started losing rpm's got back to dock, #2 plug had exploded and fried plug wire. Bought NGK's no problems since. Now I wonder, should I have purchased the plugs at a auto parts store? I bought them at Boater's World and paid a premium for them. Shouldn't all plugs be created equal? :D
Of course I wasn't saying there was any difference in plugs between the boat shop and the autoparts store - just that the autoparts store probably has cheaper prices, and for me at least, is much, much more convenient (e.g a minute from my office vs. a 50 minute round trip across town). As for the problem you had, I have no idea. The only time I've ever had problems with a plug - whether they be NGK, autolite, champion or whatever is used in the various cylinders I have - is because I damaged it or put it in wrong. But I'm a ****ty mechanic and have that sort of problem with everything I try to "fix".
 

midsized johnson

Petty Officer 2nd Class
Joined
Jul 28, 2005
Messages
155
Re: NGK plugs

Originally posted by D.:<br />
Originally posted by Mid-size Johnson:<br /> When I got my Johnson, I put required Champion plugs in. I ran it once, one of the plug's ceramic came loose. Replaced that plug, ran motor again, started losing rpm's got back to dock, #2 plug had exploded and fried plug wire. Bought NGK's no problems since. Now I wonder, should I have purchased the plugs at a auto parts store? I bought them at Boater's World and paid a premium for them. Shouldn't all plugs be created equal? :D
Of course I wasn't saying there was any difference in plugs between the boat shop and the autoparts store - just that the autoparts store probably has cheaper prices, and for me at least, is much, much more convenient (e.g a minute from my office vs. a 50 minute round trip across town). As for the problem you had, I have no idea. The only time I've ever had problems with a plug - whether they be NGK, autolite, champion or whatever is used in the various cylinders I have - is because I damaged it or put it in wrong. But I'm a ****ty mechanic and have that sort of problem with everything I try to "fix".
Apparently, I only know how to install NGK's as they didn't explode like my Champion did. No offense taken to the guy who inferred that I installed them incorrectly. <br />As for stating that I should have purchased them at an auto parts store, I was only half kidding. I think the plugs I purchased at Boater's World were faulty. A friend of mine that sells ignition systems told me that he had been having trouble with recent purchases of Champion plugs.
 

solberg

Cadet
Joined
Aug 30, 2005
Messages
11
Re: NGK plugs

Wow, didn't mean to start anything. The town my cabin is by has only one parts store in it, and they didn't have the right size in champions. Otherwise that is what I was going to buy. But I realy didn't think that it mattered that much of the brand, just so you had the right size.
 

moderator1

Lieutenant Commander
Joined
Dec 5, 2002
Messages
1,668
Re: NGK plugs

It seems a few of you understand the plug "size" must be correct, but the internal resistance and how the plug dissapates heat is the key. For a particular P/N NGK, there IS NO replacement in another brand that has the exact charactoristics, and the same is true of Champion and other brands as well.<br />The myth of champion plugs is a result of improper torquing, and has been proven time and again over the years.<br />"No thanks" to Champion plugs is a needle in a haystack example. Monoshock, do you know what the torque specs are for Champion or NGK???
 
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