Spark plug confusion

john3931

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I am in the beginning stages of checking out an engine for a boat that I am getting for my favorite price.:)
It is a Mercruiser 228 with a serial number of 6021325. According to what I have able to find out was manufactured between 1979-1982. Looking at a Champion cross reference it should use either 5942 marine plug or RV15yc4 standard plug. Both these plugs have extended electrodes. The plugs presently in the engine are RV8C that do not have extended electrodes.
Did someone use these plugs because they had them around from their John Deere?:)
 

Don S

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Re: Spark plug confusion

AC- MR43T is what is called for for your engine. You really don't want champions in it. They might work in lawn mowers, cars, a such, but I have had a lot of problems with them in boats.
 

bigbob_FTW

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Re: Spark plug confusion

AC- MR43T is what is called for for your engine. You really don't want champions in it. They might work in lawn mowers, cars, a such, but I have had a lot of problems with them in boats.


that is, unless it's a johnson or evenrude. Then they are a must.
 

APPALOOSA2

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Re: Spark plug confusion

Engine manufactures spend a lot of time testing and getting the engine ignition to exact specs with the brand the use.
GM always AC
Ford always Motorcraft
Chrysler always Champion

I have seen many problems from same heat range plugs but different brands.
 

Bondo

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Re: Spark plug confusion

Ayuh,... The AC Delco MR43T are the plugs you want... They're an Alloy body...
 

Gary H NC

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Re: Spark plug confusion

Just did a tune on a Merc 4.3.....It had NGK plugs in it that looked really bad.
Rusted like crazy and the electrodes looked terrible.
Put new AC plugs in and it starts with a bump of the key.
The customer said it has never started that easy in the 4 years he has owned it..:rolleyes:
 

john3931

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Re: Spark plug confusion

Thanks for the info. I knew it called for the AC MR43t. Just wanted to make sure there wasn't some old mechanic trick.:)

I have been trying to download a manual from the Adult section but nothing seems to be happening.

Is there a problem?
 

mark1905

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May 25, 2008
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Re: Spark plug confusion

Spark plug brand loyalty seems like oil brand loyalty and belly buttons.. Everyone has one.

I personally can't stand AC plugs.. I've had bad experiences with the ceramic electrodes cracking for no apparent reason. Switched to Champion only in all my marine motors and have never had a problem..
 

Bondo

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Re: Spark plug confusion

I have been trying to download a manual from the Adult section but nothing seems to be happening.

Is there a problem?

Ayuh,... Other than they're pdf. files that take Forever,...??.. Nope....

Try right-clicking,+ choosing "Save to Disc" or "Save target As" or whatever option you have...
 

APPALOOSA2

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Re: Spark plug confusion

Spark plug brand loyalty seems like oil brand loyalty and belly buttons.. Everyone has one.

I personally can't stand AC plugs.. I've had bad experiences with the ceramic electrodes cracking for no apparent reason. Switched to Champion only in all my marine motors and have never had a problem..

Well I don't want to get into a pissing match but I have worked at a dealership for 30 years and when a customer comes in with runs like crap just did a tune up first thing is the plugs.


I have seen countless times over the years ,changed plugs to another brand and 9 times out of 10 its the plugs.

Oil is a whole another story and I wont go there !
 

Gary H NC

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Re: Spark plug confusion

No pissing match here but a cracked AC plug could be from whoever installed them..I have cracked a few myself over the years.
As far as quality the Champions are bottom of the scale in my opinion.
Only thing i use them in is my outboard that calls for Champion only.The old surface gap plugs.
 

ne7800

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Re: Spark plug confusion

oh heck i'll throw my two cents in lol i run champions in everything i own always have, even in my "dreaded" merc 470 havent had any problems yet, doesn't meant it's the right answer just means i havent had any problems
 

Gary H NC

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Re: Spark plug confusion

oh heck i'll throw my two cents in lol i run champions in everything i own always have, even in my "dreaded" merc 470 havent had any problems yet, doesn't meant it's the right answer just means i havent had any problems

As long as they work for your motors great!!:D

Its funny how some motors just don't like some brands of plugs.

My motorcycle is the same way.It only runs right with NGK Iridium..
The factory Denso plugs kept fouling.

Went to the dealer one day to pick up the 4 spark plugs and they wanted 21 bucks each!!! I can order them through the auto parts store for 9.99..:rolleyes:
 

ne7800

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Re: Spark plug confusion

My Champion loyalty probably comes from the fact that i own (and have owned) a lot of Dodges, Chrysler uses champion in there engins
 
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