What spark plugs do you use?

M

mysticowner

New Member
Feb 19, 2011
213
Huntingdon Pa.
Boat Info
23' cuddy cabin jet boat. 92 270 Sundancer waiting
for the maiden voyage
Engines
545 big block ford 600+ HP. Stroker 270 is the 454
Our 92 sea ray 454 has AC-MR43T Plugs listed on the air cleaner cover.
Do you fellows use these plugs or maybe the champion RV8C
or NGK BR6FS (If these numbers aren't right please feel free to holler.)
Or are the AC's OK?
Thank you in advance :smt100
 
I only use what is OME spec. Mind you, my original spec called for AC Delco and now its NGK. Apperently AC is not producing the plus for my engine anymore. Even the Mercruiser part number for the plugs has changed. The new number is for the NGK Irridium plugs. Chevy "marine" engines are very picky about the plugs. If they are slightly off in size, gap, heat, etc... they just don't run right.
 
ardeprint said:
I only use what is OME spec. Mind you, my original spec called for AC Delco and now its NGK. Apperently AC is not producing the plus for my engine anymore. Even the Mercruiser part number for the plugs has changed. The new number is for the NGK Irridium plugs. Chevy "marine" engines are very picky about the plugs. If they are slightly off in size, gap, heat, etc... they just don't run right.
Click to expand...

It is likely they were just supersceeded with a new part number. Based on personal experience and advice of many mechanics over the years, I use only AC Delco Plugs in GM Engines, Marine or otherwise. NGK are best used in Japannese engines.


Have a look here- http://ww2.justanswer.com/uploads/ROCKETBOAT/2008-12-09_042519_SPARK.pdf

and here- http://clubsearay.com/showthread.php/25595-Purchasing-Spark-Plugs-Who-s-amp-Wher
 
Use the AC's! I worked at a GM dealer years ago when spitfire plugs were popular. We had a truck in a shop that we couldnt figure out why it wouldnt run right. After all our diagnostics we replaced the plugs with AC's and problem went away. Saw many more until the gimicky plugs became well known as being just that. Have also seen some issues with Champions. Good for lawn mowers, not so much for for automotive motors.
No personal issues with NGK's, but the AC's have always worked for me. Just my .02
 
I now use the ACMR43Ts. I've used the Champions and Autolite 25s. Never noticed any difference but I'm drinking the "marine sparkplug" koolaid, even though I don't fully buy into the concept of "marine" sparkplugs. Sorry.
 
I am using AC Delco 41-993 Iriduim Plugs and love them. They are (or were in 2010) the most up to date Merc Recommended plug for my engines. The 41-993 was available in Platinum and Iridium. I have read here that you can foul iridium plugs of you fog. I don't fo so I went with the Iriduim.
 
Now Ronald! If you ever run into a standard auto plug that hasnt been replaced in years and the steel has rusted to the block, you'll wish they had the marine plug. I had this on my old bowrider. The plugs had been in there a while and were a biznatch to get out. Other than that same plug. If you change them every year or two and coat thread lightly with antiseize, probably no problem with auto MR43's


rondds said:
I now use the ACMR43Ts. I've used the Champions and Autolite 25s. Never noticed any difference but I'm drinking the "marine sparkplug" koolaid, even though I don't fully buy into the concept of "marine" sparkplugs. Sorry.
Click to expand...
 
Touche' Mark - HOWEVER, that would never happen to me b/c I replace them every 3 seasons. AND I put Never-seeze on the threads. But for the lazy and neglectful, you are correct!

My 99 cent Autolites from Wallyworld worked flawlessly - now I pay twice as much for my "marine" plugs b/c of that letter "M!"
 
jason78 said:
It is likely they were just supersceeded with a new part number. Based on personal experience and advice of many mechanics over the years, I use only AC Delco Plugs in GM Engines, Marine or otherwise. NGK are best used in Japannese engines.


Have a look here- http://ww2.justanswer.com/uploads/ROCKETBOAT/2008-12-09_042519_SPARK.pdf

and here- http://clubsearay.com/showthread.php/25595-Purchasing-Spark-Plugs-Who-s-amp-Wher
Click to expand...
NGK has been the standard plug in many (not all) GM engines since the late 90s
 
I was told my tune up this Spring will require 16 sparkplugs @ 16.00 each
Click to expand...

Is that including labor? I sure hope so!
 
Just say no! You have a rachet set and 2 hours? You can get some of them fancy schmancy "MARINE" plugs and screw them in yourself! Amazing how changing spark plugs is called a "tune up." No points or condensors to diddle with anymore, no other ignition components will be changed. I have no problem with a mechanic making a living, but paying someone $500 to unscrew and rescrew in spark plugs? Fuggeddaboudit!
 
rondds said:
Just say no! You have a rachet set and 2 hours? You can get some of them fancy schmancy "MARINE" plugs and screw them in yourself! Amazing how changing spark plugs is called a "tune up." No points or condensors to diddle with anymore, no other ignition components will be changed. I have no problem with a mechanic making a living, but paying someone $500 to unscrew and rescrew in spark plugs? Fuggeddaboudit!
Click to expand...

I agree! In fact, since we are on this thread. When I went to change the plugs and noticed that $14 price tag I was VERY tempted to go and buy the equivalent plugs automotive. But.... I have had problems using non spec plugs so I bit the bullet.

I did the swap myself and had no issues.
 
Last edited:
ardeprint said:
I agree! In fact, since we are on this thread. When I went to change the plugs and noticed that $14 price tag I was VERY tempted to go and buy the equivalent plugs automotive. But.... I have had problems using non spec plugs so I bit the bullet.

I did the swap myself and had no issues.
Click to expand...

In regards to the "marine" plgus, please go to this thread and read post 1-7. Post 6 is made by Dennis who is a Sea Ray/Mercury Dealer. I am a big advocate of using "marine" rated on almost ever componet. Spark Plugs are not one of those.

http://clubsearay.com/showthread.php/25595-Purchasing-Spark-Plugs-Who-s-amp-Wher
 
Any plug but Champion. If you ever flood the engine you can forget about restarting without replacing them. Autolites or NGK's you can dunk in a gas can and install them and they will light up.
 
I've used Champion, NGK, Autolite, and AC. I've never had an issue with any of them.
 
You must log in or register to reply here.

Forum statistics

Threads
113,206
Messages
1,428,562
Members
61,109
Latest member
Minnervos
Back
Top