Obsolete spark plug

[Celeb92]

Hi guys and gals. I'm doing a little fall maintenance but ran into a minor problem. The factory manual for my 5 liter, 210 hp chevy (Yamaha rigging) specifies AC-MR44T spark plugs. The PO gave me a spare set which I installed last year but am now looking for replacements. I've been told that those plugs are no longer made. Any suggestions for the "best" replacements? I favor NKG brand but would appreciate any suggestions for any brand. And, any good links for plug references or guides. Thanks in advance.

 

[12vMan]

Re: Obsolete spark plug

I've always had great performance with NGK and always recommend them.

 

[seaboo]

Re: Obsolete spark plug

I just did a quick google search and found that ac, champion, and Ngk all make a replacement plug. If it were me I'd go to a "good" auto parts store and ask them for a plug that cross references. I do agree with you, I'd go with Ngk's given the choice.

 

[victorc1]

Re: Obsolete spark plug

My advice is don't use automotive plugs, use marine they are stainless steel and don't get rusty. offshorewakemarine.com look here.

 

[Howard Sterndrive]

Re: Obsolete spark plug

MR44T isn't obsolete

 

[12vMan]

Re: Obsolete spark plug

MR44T isn't obsolete

True - Maybe iboats has it or a cross-reference or you can find it in a couple of clicks otherwise.

 

[Celeb92]

Re: Obsolete spark plug

Thanks all -- but maybe I should rephrase the question a bit. Since the 5 liter chevy is so common, I was hoping that someone could suggest a specific brand and sku for plugs that they have found to be excellent in a marine application. There are many posts on this forum that knock AC and some other brands of plugs so even if I could find the MR44T's, I'd prefer a "better" replacement. Yes, I can goggle (bing?) cross reference charts but each is published by the competitor manufacturer and there are enough differences between brands that those kinds of charts are approximations. I'd much rather have someone's recommendation for a specific plug that they "swear by" instead of at. Any suggestions/recommendations?

 

[cr2k]

Re: Obsolete spark plug

SS spark plugs? Huh. Not sure about Marine Plugs?

NGK does make the best plugs in my opinion.

Just don't fall for any of those fancy twin fire or plugs like that. They are a rip.

 

[Bondo]

Re: Obsolete spark plug

I'd prefer a "better" replacement.

Ayuh,... as noted, the AC Delco MR 44T is not obsoltete,+ Is the Best plug for your application...
That's Why is was spec'ed for the motor...
And,...
Yes, that's the difference between the R44T Vs. the MR44T, the body of the plug is an Alloy....Not just plain ole steel...

 

[Don S]

Re: Obsolete spark plug

NGK BR6FS is what Yamaha calls out for the 5.0L engines.

 

[Gary H NC]

Re: Obsolete spark plug

How about 2 bucks each...? Put in ACMR44T under the part# search...
If you buy 8 or more they are 1.68 each...

http://www.rockauto.com/catalog/raframecatalog.php

 

[shogun95]

Re: Obsolete spark plug

Out of curiosity, why are you changing the plugs again this year? How many hours did you run it this year?

 

[Celeb92]

Re: Obsolete spark plug

As always, great info from helpful people on this forum. In response to some of the responses -- yes, the AC-MR44T is the plug identified in the "real" factory manual (not a Seloc type manual). Nice to know that this plug is still available - not what I was told by the counter person at my local marina. Assuming that I needed to find an alternative to the factory spec'd plug, and given the number of times that AC and Champion plugs are dissed on this forum, I was looking for recommendations on almost anything else you guys and gals have had good luck with. And, to answer one post, I plan to change the plugs every year -- just a bit anal from all of the years that I was involved in road race and drag race cars. New plugs are cheap as part of an insurance package for reliable (and safe) operation. Thanks again - I may still go with the NGKs.

 

[mdlee]

Re: Obsolete spark plug

GO with the NGKs.. I never had a major prob with NGKs,,,, I cant say that for the others

 

[MRS]

Re: Obsolete spark plug

Any of my G.M. or G.M.C. motors always gets AC plugs NGK is always a good second but AC is always first choice......

 

[D_J_Winn]

Re: Obsolete spark plug

just my 2 cents, Use what works well in your engine. I know through personal experience champions run hotter than NKG in my engine, don't really know why.

boatingaccessoriesus.com MR44T 3.68 a piece