Mercury 6.2 spark plugs

[gapple12]

I’m in the process of doing a tune up on my 6.2 and noticed the standard spark plugs are discontinued and they recommend the NGK laser Iridium ITR4A15 5599 plugs. Once I got them I realized you don’t gap them. Anyone have experience with these ?

 

[gapple12]

These would be considered aftermarket, the original plugs dont show available on marineengine web site.

 

[Bondo]

Ayuh,.... Exactly which spark plugs did ya find in the motor,..??
Post a picture of 'em,...

If they were fancy spark plugs like yer wantin' to put into it,....
The ole 1s probably still have several thousand hours left in 'em,....
As that's the only reason for such spark plugs,....

If ya don't care 'bout the longevity, plain ole AC Delco, MR43TLS will run just fine, for several years,...
Or,... MR43T if the heads are Pre-Vortec heads,....

 

[gapple12]

Ayuh,.... Exactly which spark plugs did ya find in the motor,..??
Post a picture of 'em,...

If they were fancy spark plugs like yer wantin' to put into it,....
The ole 1s probably still have several thousand hours left in 'em,....
As that's the only reason for such spark plugs,....

If ya don't care 'bout the longevity, plain ole AC Delco, MR43TLS will run just fine, for several years,...
Or,... MR43T if the heads are Pre-Vortec heads,....

I will find out this weekend when I pull them. I dont want to run plugs that will make the motor run different, (SN#OW388329) I've never seen plugs that you dont gap in a boat. When I buy a boat, I typically do plugs, wires, cap and rotor, impeller, fuel filter, and belts. I know its probably over kill on some of this, but just makes me fell better not getting stranded on the water with my kids. I keep the old parts on hand just in case.

 

[scoflaw]

Iridium is what you want. They're expensive but last a long time. I wouldn't just replace them for the hell of it.

You don't gap them either.

 

[Bt Doctur]

People use them because that dont want to be bothered with MAINTANCE of their motors
plugs make a spark, thats all.
Pick one
http://www.sparkplug-crossreference.com/convert/AC_DELCO/41-932

 

[Scott Danforth]

not a thing wrong with the NGK's and yes, they are factory-gapped because of the iridium electrode (because shade-tree mechanics tend to booger up the electrode trying to gap them, so they come ready to go)

 

[Bondo]

I will find out this weekend when I pull them. I dont want to run plugs that will make the motor run different,

Ayuh,.... Whether ya run the Iridium(which are factory gapped), or the traditional plugs I mentioned,.....
The motor will run Exactly the same,.... No difference, at All,....

It's 'bout the longevity,.....
The Iridium plugs are a lifetime plug, never change 'em, 2,000 hours Plus,..... 100,000+ miles in a truck,....
The traditional plugs I listed are more like 500 to 1,000 hour spark plugs,....

It comes down to spark plugs that fit the head drillin's,....
Chevys have nearly forever been the AC MR43T marine plug,....
In '96, with the Vortec heads, the slightly longer AC MR43TLS was required,....

Boaters just Love to throw away perfectly good Spark Plugs, 'n Coils,.....
Boat ramp dumpsters are full of 'em,....

 

[Scott Danforth]

99.99999% of the time its NEVER the coil

 

[alldodge]

First don't change the plugs
Second do change the distributer cap (8M6001106), they go out without warning. Keep the old one in the tool box

Your serial number shows
Mercruiser parts site shows ITR4A15 (33-8M2018369) as the correct plug

 

[QBhoy]

It’s AC Delco 41-993 you are after for best value. You can get NGK but they crazy money. Also part number PZTR5A-15
that said, you don’t need to change the plugs on the mpi every year like the carb. Only if you in doubt about them or for trouble shooting.
As All dodge says, more pro active changing would be best spent replacing Diz cap and rotor every year to give piece of mind reliability....or certainly carry a spare. It will let you down at some point. Hopefully near the shore like mine did ! Others have been less fortunate with Diz cap let downs.