Weird, I just looked up the spec of plug that mercruiser shows for my year boat and it is different from what I have in there.
They show an AC 41-932 - and that cost on this website is $16 per.
My mercruiser mechanic installed what's in there now a few years back, so I have to assume it's right. And the motor has purr'd for years.
But, it sounds like there is something going on with price of these plugs.
Is there a way to 100% confirm what plug I should have in there ?
41-993 is now the newest plug # for your engine.
Back around 06 Merc superseded AC 41-932 to 41-993.
http://ww2.justanswer.com/uploads/ROCKETBOAT/2008-12-09_042519_SPARK.pdf
As for the price of the plugs, yes for some reason the Mercruiser factory does sell them at a much higher price even to their dealers then what you can find them for either online or calling around the local auto stores or even a GM auto dealer sales them for less I believe I have heard.
There is no difference between buying the AC 41-993 plug from a Merc dealer or anywhere else I mentioned above except the price is all. In this case the plugs are the same for both truck and marine.
It's possible your Merc dealer just may have been used to seeing the older prices of around the $19.50ish mark the plugs used to be a few years ago and quoted you the old price that he probably marked on the box when he received them at the higher price a few years ago. Also it's quite possible that your guy has not looked recently at the price of these plugs lately, Becuse they since have been coming down in price a little bit over the years.
Technically speaking the Mercruiser dealers are supposed to buy them from the Mercruiser factory in order to be covered/Backed up by the Mercruisers parts warranty program when things go wrong.
So technically speaking the Mercruiser dealer is supposed to sell or install the plugs they bought from the Mercruiser factory, even at the higher prices the factory sales them to their dealers.
Right now the MSRP from the factory is $16.25 each.
And right now if you tried to order in a new set of plugs from the factory you would receive Merc's newest part number 33-8M2018369 which turns out to be a NGK spark plug. (NGK ITR4A15)
@4 per box.
The item supersession chain numbers for this part are,
(1) 33-8M2018369 NGK ITR4A15 @4 (Newest)
(2) 33-884019001 AC 41-993 @8 (Middle)
(3) 33-884019 AC 41-932 @8 (Oldest)
