# Spark Plugs, Worth the Difference?



## fishnpreacher (Jul 28, 2018)

I'm replacing the spark plugs in my motor, '98 Mariner 40hp 2 stroke. Factory specs the NGK BP8H-N standard spark plug. Are the iridium, platinums, or other "high performance" spark plugs worth the difference? Any downside to hi-performance plugs?
I did a search for spark plugs and understand plugs can mess with electronics, but just wondering about overall performance.


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## TheAdamsProject (Oct 29, 2007)

I’ve never gone wrong using what the manual says. Would be curious to hear other recs though.


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## Copahee Hound (Dec 21, 2017)

Based on my auto tech experience, always use the spark plug that the engineer designed the engine to run with


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## Smackdaddy53 (Dec 31, 2012)

They are cheap, get the recommended plugs.


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## topnative2 (Feb 22, 2009)

https://www.carparts.com/blog/iridium-vs-platinum-spark-plugs/


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## fishnpreacher (Jul 28, 2018)

I have found 2 factory spec'd plugs. 
1. the one in my first post, traditional NGK BP8H-N, about $3.00
2. NGK BUZ8H. This is a surface gap plug, about $11.00
Despite the obvious, what's the difference?
Which one would you choose?


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## Smackdaddy53 (Dec 31, 2012)

If they both fall in factory spec and you are feeling froggy jump on those $11 plugs. $9 vs $33 isn’t that big of a gamble. I run the NGK plugs that are in the manual and have no issues. Running good fuel and oil is more important than fancy plugs IMO.


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## fishnpreacher (Jul 28, 2018)

Thanks everyone! 
$9.00 worth of plugs coming up


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## Redfishonthefly (Nov 12, 2016)

fishnpreacher said:


> I'm replacing the spark plugs in my motor, '98 Mariner 40hp 2 stroke. Factory specs the NGK BP8H-N standard spark plug. Are the iridium, platinums, or other "high performance" spark plugs worth the difference? Any downside to hi-performance plugs?
> I did a search for spark plugs and understand plugs can mess with electronics, but just wondering about overall performance.


BPZ8- can make a very slight difference, if you want to gain a little power that’s reliable and safer for the motor run Boyesen 2 stage carbon fiber reeds. We put them in every motor we build.


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## loganlogan (May 8, 2020)

It would really make for a bad day, if you saved $20 on plugs but had to pay for a tow back to the dock.


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## State fish rob (Jan 25, 2017)

Not sure but , I think the buz8h are more for aluminum heads. E3 ’s. She’ll fly......


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## Redfishonthefly (Nov 12, 2016)

Redfishonthefly said:


> BPZ8- can make a very slight difference, if you want to gain a little power that’s reliable and safer for the motor run Boyesen 2 stage carbon fiber reeds. We put them in every motor we build.


The only difference in the BPZ‘s is that it has a slight cleaner spark, it is the exact same plug your running now with a v in the center electrode, you can look on NGK web and that plug will cross reference with what your factory recommenders, I’ve been running them in my Yamaha for 3 years with 0 issues . I build 10-20 mercury and Yamaha motors every year, and it’s always peeps messing with, advancing the timing or carburetor leaning the motor, also oil objectors failing or prime start on Yamaha failing.


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## Smackdaddy53 (Dec 31, 2012)

The reason I recommended he look at recommended plugs for his engine.


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## Redfishonthefly (Nov 12, 2016)

Smackdaddy53 said:


> The reason I recommended he look at recommended plugs for his engine.





Smackdaddy53 said:


> The reason I recommended he look at recommended plugs for his engine.
> [/QUOTE coming from a certified Mercury mechanic of 35 years ! There absolutely could be some benefits to running the NGK Dash BPZ ‘s, it could clear up hesitation or even slight skips in a two stroke outboard, the factory recommendeds bar blog was developed in the early 90s wear the NGKBPZ was developed much later to help with unburned deposits and two stroke outboard‘s. Will he see any performance difference, probably not is it as reliable as the recommended spark plug,absolutely.


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