Which spark plugs to use?

[texasvet54]

I just pulled some Champion RS14YC plugs out of my 5.7L Mercruiser and I was about to replace them with the same.

I looked at the specs for my engine and they call for an RS12YC plug.

Which one should I use?

Thanks,
Texasvet

 

[achris]

Re: Which spark plugs to use?

Mercury use the 350 chev engine from the 1970s and in that time they have seen MANY changes... including different spark plugs.... What year, or better still serial number, is yours?

 

[Don S]

Re: Which spark plugs to use?

Never, Never,Never,Never,Never,Never,Never, ever use Champion spark plugs in a marine engine, unless you like to spend time looking for misses, and having poor running problems all the time. Stick with the AC or NGK spark plugs.

 

[achris]

Re: Which spark plugs to use?

Never, Never,Never,Never,Never,Never,Never, ever use Champion spark plugs in a marine engine, unless you like to spend time looking for misses, and having poor running problems all the time. Stick with the AC or NGK spark plugs.

So Don, what do you think of champion spark plugs????

 

[texasvet54]

Re: Which spark plugs to use?

Mercury use the 350 chev engine from the 1970s and in that time they have seen MANY changes... including different spark plugs.... What year, or better still serial number, is yours?

Hello Chris,

It's a 1999 5.7L Mercruiser. The S/N is 0L060433.

I'm going to take Don's advice and go to Advance Automotive and see if they have the NGK plugs.

Thanks,
texasvet

 

[Don S]

Re: Which spark plugs to use?

AC - MR43LTS or NGK - BPR6EFS is what you want.

 

[texasvet54]

Re: Which spark plugs to use?

AC - MR43LTS or NGK - BPR6EFS is what you want.

Don,

Any suggestion on wires and distributor cap?

Texasvet

 

[Fordiesel69]

Re: Which spark plugs to use?

How about for a 1985 year chevy 350's with the perimeter bolt valve covers? Which part #?

I have to do the same.

 

[achris]

Re: Which spark plugs to use?

How about for a 1985 year chevy 350's with the perimeter bolt valve covers? Which part #?

I have to do the same.

You should start your own thread, but the right plugs for you are NGK BR6FS or AC-MR43T...

For a dissy cap, you need to get a MARINE cap, probably a Merc dealer would be best (I don't know about after-market in the U.S.). Plug wires can be anything, I prefer silicone these days. Prior to silicone being widely available I'd use solid wire, but NEVER carbon leads...

Chris........

 

[mark1905]

Re: Which spark plugs to use?

AC - MR43LTS or NGK - BPR6EFS is what you want.

You should start your own thread, but the right plugs for you are NGK BR6FS or AC-MR43T...

Whoa whoa.. for the sake of preventing catastrophic engine failure due to piston/plug contact..

It should be noted that the NGK BR6FS and the BPR6EFS are very different plugs and made for different applications. The "P" stands for "Projected".. as in.. one is physically longer than the other. ALWAYS verify your exact application first!!

Also.. the BPR6EFS (17.5mm seat reach) and the BPR6FS (11.2mm seat reach) are of course two different plugs and different from each other..


This may sound like a "DUH.. of course".. but it never hurts to re-iterate this point.

 

[achris]

Re: Which spark plugs to use?

Whoa whoa.. for the sake of preventing catastrophic engine failure due to piston/plug contact..

It should be noted that the NGK BR6FS and the BPR6EFS are very different plugs and made for different applications. The "P" stands for "Projected".. as in.. one is physically longer than the other. ALWAYS verify your exact application first!!

Also.. the BPR6EFS (17.5mm seat reach) and the BPR6FS (11.2mm seat reach) are of course two different plugs and different from each other..


This may sound like a "DUH.. of course".. but it never hurts to re-iterate this point.

Hey Mark,

Not sure of the point of your post... The original poster has been given the right plugs for HIS engine... FD69 then asked about his... I gave him the right plugs for HIS (different) engine... I also advised him to start his own thread.... Where's the problem?

Chris......

 

[Jlawsen]

Re: Which spark plugs to use?

Never, Never,Never,Never,Never,Never,Never, ever use Champion spark plugs in a marine engine, unless you like to spend time looking for misses, and having poor running problems all the time. Stick with the AC or NGK spark plugs.

Ironic isn't it that Merc ships their motors with Champion plugs. My 2011 60hp EFI came with them and seems to be just fine. I troll that thing all day sometimes and it never skips a beat. It could be that I'm pretty meticulous with my maitenance that makes the difference but I suspect you are too.

I've heard all the bad things about Champion plugs and this is the first Merc that I've run them in and so far no problems. I always carry an extra set in my emergency kit but I'd do that if I was running NGK's too.

 

[Don S]

Re: Which spark plugs to use?

You have an outboard, this is a Mercruiser forum. Mercruiser comes with OEM GM plugs in them. Not Champion. And Champion plugs don't like GM engines for some reason. I have done nothing more than replace Champion plugs for years to replace running problems. Many of those pluges were installed by the owner and he had no clue why his engine lost power and missed. I have also replaced a bunch of them that had the porcelain blown out of them.

 

[Fordiesel69]

Re: Which spark plugs to use?

Don,

Question......I know that any plug will not tolerate a spray or drop of water when they are hot. Is it the champions fail from this or are they just that bad. All my 4cyl, 6cyl, have old ones in and they have never failed. My omc has champions and they were completely shot, but definatly lived long. My logs make it so water can not drip or fall on them to crack the porcelin. NGK used to be #1 but I have have the opposite, my power washer, snowmobile, tractors, etc all go thru NGKs left and right. Champions never Wierd!

Maybe I will start using AC delco in the merc engines. Is there any problems with those?

 

[Don S]

Re: Which spark plugs to use?

Fordiesel69, You really need to start your own thread as Chris mentiond, and stop hijacking this one.

http://forums.iboats.com/announcement.php?f=21