Spark Plugs

[RSHOOTER]

I have a 2007 Glastron with a 3.0 4cyl Mercruiser GM engine. The Manual calls for an AC-MR43LTS spark plug. When I went to NAPA they sold me an
AC Delco #8 Platinum plug which they said was equivalent. Is this true?
What does Platinum do for a plug?

 

[Don S]

Re: Spark Plugs

Never heard of an AC plug with just one number before, or is that #8 part of the plug number? Like MR43LTS8.
If that is the case, it's got a .080 preset gap. Take it back and get the correct plugs, because you only need a .045 gap.

 

[180shabah]

Re: Spark Plugs

What does Platinum do for a plug?

It doesn't erode as fast, so the plugs last longer. Of course that won't matter if you don't have the right plug to start with.

 

[TilliamWe]

Re: Spark Plugs

I'm with Don, the only single number AC Delco plugs I have ever seen are the Rapidfire series.
It's surprising they didn't just order the MR43LTS for you? NAPA is who I have get my marine plugs, when I have needed them.

 

[RSHOOTER]

Re: Spark Plugs

They are AC Delco 8# Rapid Fires and will gap .045. The box has 8# on it...the only other number is 19145290. The plug just has an 8. NAPA local store claims they are equivalent but I can't find a Chart. Has anyone used these for MR43LTS? Unless I can get more info I will probably go back to the MR43LTS.

 

[RSHOOTER]

Re: Spark Plugs

Found New Info!
RapidFire ACD No 8 Sparkplug 19145290
Item #19145290
19145290 ACDelco RAPID Platinum Spark Plugs have been redesigned for improved performance your vehicle demands, for longer life and optimum efficiency.
Replaces ACDelco standard numbers: R42LTS, R43LTS, R43LTS6, R42LTSM, R43LTSM, R42LTS6, and MR43LTS.
MSRP: $5.23 Your Price: $4.25
It says it's a direct replacement.

 

[JustJason]

Re: Spark Plugs

just a note about platinum plugs....
In alot of cases.... if the engine is designed to use standard plugs, its not going to have enough juice in the ignition coil to get the platinums hot enough to be self cleaning. and they will actually foul up quicker than standard plugs.
In any case(boats or cars).... you should always stick with what the manufactor says... no matter what. And no matter what the guy at napa tells you. The guy at napa wasn't one of the 50 engineers that designed the powerplant, and neither are we. Your best bet is to just follow the instructions and use what the manufactorer engineered the system to use.
Using platinums in boats, with engines designed not to use them, can actually lead to detonation because even though they claim they are the same heat range, they can and will run hotter... they are designed to.

 

[TilliamWe]

Re: Spark Plugs

Since they x-reference to an R43LTS, they will work just fine, shooter!

I did not realize that Rapidfires were platinum.