spark plugs, which are best for boats?

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Eric B

Well-Known Member
Mar 1, 2001
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cant remeber what came with the boat, but it is like 3 letters. anyways, ive
always used motorcraft plugs in my truck, champions dont last long for me
and i now have motorcraft in the 40hp Merc.

I changed them when I went to synthetic oil, now... it runs funny. I think i
posted this before. anyways, what are better plugs for 2 cyc mercs?
You're probably thinking of NKG's.....a lot of people use them....just use the dealer recommended plugs in your owners manual. You'll never go wrong with the manufacturer recommendsed parts......good luck this season!!
Eric -

There isn't a gnat's derriere worth of difference in the performance you'll see out of any of the major brands. Buy whatever is easiest for you to obtain.

Don't waist your money on any of the "Super" plugs either...... If you notice any difference - it'll all be in your head!

Spark plugs for outboards are expensive enough as it is!

Scott, shame on you. You know better than that.

The marine plugs by Champion and NGK are designed specifically for a particular motor or series/design of motors. If the manufacturer says use a Champion QL78YC or an NGK BU8H, then you are shooting yourself in the foot if you use anything else. These are the plugs that will perform the best and last the longest in those particular motors. Period.

Personally in a Mercury i wouldn't run anything but NGK's i've found that NGK seams to run smoother and burn a bit cooler then their champion counterparts.... thats my 2 cents worth but... what do i know... i just fix um :)
Forgot to add..... On the other hand... if your running a OMC go with the champions...
Scott, my friend, it just ain't true. There isn't a plug on the market that will cross over and perform as well throughout it's lifespan on a Merc 150 as a BU8H from NGK. The same holds true for a 60 Degree OMC 150 and a QL78YC from Champion. These plugs were not just made by the manufacturer. They were made to the boat maker's specs.

I am constantly amazed that someone who spends thousands of dollars on a motor would want to take chances with a $5.00 part that is changed at the most, once a year. It just doesn't make sense. In a Mercury, except for the Optimax, the plugs will range from $2.95 to $8.00 apiece. So, assuming your motor uses something that hits in the middle at $5.00 each and you can get a crossover that will work in your motor for $4.00 each. If you're running a V6, that means you have saved $6.00 in a tuneup. Considering that we do a tuneup normally not more than once per year, six dollars seems a pitifully small amount to save to take a chance with your motor.

I'm like Chris. Ask the people who make them and who work to make them run their best. They will all tell you to go with the manufacturer's recommendation.

Can you get by with a different plug? Probably. Is it worth the hassle and possible problems? Not to me.

Jim and Chris -

Until someone can show me tests from an indepnedant source - I will stand by what I said: "There isn't a gnat's derriere worth of difference in the performance you'll see out of any of the major brands."

If you can find such test results, I will publicly eat crow fried between the electrodes of your favorite plug! But, lacking that, I will just give Two Thumbs Up to the Marketing Departments at NGK and Champion - you guys have done one very good job!

Chris, you're missing the point. The point is that the manufacturer has asked a spark plug maker to make a particular plug to a particular spec. The plug maker does it. Now, does another maker make a similar plug? Sure. But I can tell you from real life experience that OMC 60 degree motors that use the QL78YC Champion will not run right with any other plug and the plugs will not last as long. The same is true of Mercury V-6's that use the BU8H plug.

Then, when you get to the more exotic plugs, such as the ones for the DFI motors, there isn't even a good crossover.

I think it's just plain silly to scrimp a few dollars on a ten thousand dollar motor.

Generally, I am not a fan of Champion plugs. On the other hand, for most OMC applications, they are the only CORRECT plug to run. Period.

Like Chris, I've been doing this for a day or two.

Adam, Everyone starts out a novice boat owner, period. This is only one of two message boards I know of where you can go and get a good respectful answer to a question posed by a novice boat owner. I don't personally know Scott but he has been one of the mainstays of this board always willing to share his knowledge and I for one am great full for his participation. In a world of snotty disrespectful know-it-alls this place a breath of fresh air.
Adam, I don't censor posts and I don't contemplate kicking people of this site unless somebody goes to great lengths proving they won't adhere to the posting guidelines. Hasn't happened yet.

Like Scott, you are entitled to your opinion. Tell him you think he's wrong if that's what suits you. Just don't do it with profanity, and don't make it a personal attack.

Criticism of Tracker and Nitro products (or any other brands) are welcome, too, so long as the information is factual or clearly stated as opinion. We can all only gain when the information is honest and the posters are sincere.

In a nutshell, those are the rules. Pretty simple, huh?
Oh, almost forgot...I don't know anything significant about spark plugs.

But I do know a thing or two about marketing branded products. I don't doubt the importance of having the correct plug in a product like the Optimax, but when a manufacturer has you spending $100 for a single set of spark plugs, well, lets just say that they're always very glad to see you. Particularly the marketing department, whose annual bonuses are often tied to profit.
my merc,which is a 1987,has the origional champions in it.put new champs in it,ran like crap.put the old ones back in,runs purfect again.dont know the reason why,but it does....

my evinrude has champs in it,put champs back in it,i only paid $2 a piece for local autozone,pep boys,and advanced auto didnt have anything in stock for them,they had another plug they cross my # over to.but didint have enough to do my 90.

as for all plugs being equal,im not 100% sure on that,but my ford runs better using motorcraft plugs/autolite plugs in my crysler runs champions in it,my buick gets ac/delco plugs in it.i have aluays stuck with the plugs it came with,and never had a problem with it.guess you could say stubborn..

i have heard many people rave about the splitfire plugs,but heard many people say they are trash,no gain in hp,or mileage.but people still put them in,saying there getting the gains.but are they really?or is it in there heads they think they are getting it.

if you want to put the $22 plugs in,be my guest,im not going to say they are trash,maybe your motor calls for them,maybe they dont.but to each his own....

i read somewhere that they put in what the manual says to do,not to jepordize there 10,000+ motors,i agree with that 100%.what mine come with,goes back in all the time.if yours calls for ngk's,put them back in,champions,put them in.but what i dont believe in is the plug manufactures have a thing is we got it,you want it,you PAY dearly.they manufacture the plug per spec for the motor manufacturer,peroid.just a tweak here and there,nothing crosses to it.

as i say to each is own,if you want to put an aftermarket plug in,to save some $$$,hey its your motor,not mine,if you feel confident on doing it,more power to you...