496 MAG HO spark plugs
 

Whats everybody running as far as plugs in these things....I got a skip/miss I can't get rid of and think it might be a plug.....Whenever I do a search for plugs I get the Delco 41-983 but I'm not really liking the $15-20 each price tag that goes along with it.

When I cross reference tha number I get all kinds of different numbers depending where i cross reference from. What gives? Whats a good plug to go with? or should I just grit my teeth and go with the Delcos?

Thanks

AC Delco 41-983 gapped at .060 Auto store 6 to 9 bucks per plug. Merc store retail 15 to 19 bucks. Saved yourself some coin.

I am pretty sure the book calls for NGK plugs.

As long as they are the same heat range and length I cannot see any reason not to run the AC's.

Yes U can run NGK stock # 7164 plug type TR55IX I use them also. Also NGK rep told me that they make some of AC Delco plugs and of course stamp them AC Delco.

Straight from Merc. Service Bulletin AC 41-983 and is listed in their Service manual.

http://ww2.justanswer.com/uploads/RO...2519_SPARK.pdf

OR just google this. Mercruiser Service Bulletin 2006-03

Link works now Fixed.

I just picked up a set of AC Delco 41-983's from my local NAPA store for $5.99 each. I found a post from "Raylar" from a few years back where he recommended them, someone was looking for help with a popping sound out of the exhaust. It seems a plug had gone bad, my 496 was doing the same thing last weekend.

Link works now - Hate computers sometimes.

http://ww2.justanswer.com/uploads/RO...2519_SPARK.pdf

Back when I had my VP 496, I ordered some Iridium plugs from an online site - sparkplugs.com. Saved about $10 a piece! They should have a cross reference chart to see which ones you need. I plan on replacing 16 this spring with the same ones.

For a 496 HO up to 2006 - NGK Iridiums, part number TR55IX, $7.83 each.

Fine center electrode Platinum and Iridium tipeed plugs!
 

Just a heads up here the 41-983 Ac plug is the proper stock plug however some were made by Denso and carried a different number and any good equal platimum tip plug of the correct heat range, extension and length is a good plug.
Be very carefull when gapping small thin center electrode plugs as the center electrode should not be subjected to any pressure as it can be easily damaged in the body and result in a short lived or failed plug.
At Raylar we found a .050" gap to be the best on the 496's and we gap by carefully bending the body electrode up and down with a proper tool without putting any pressure on the fine wire center tip electrode. DO NOT use a pry type pressure gapping tool to gap these type of plugs!
Also when using anti-sieze on these plugs "a liitle dab will do you" and don't use so much that any gets on the firing end of the plug as many anti-sieze formulations will help kill spark jump across the gap and sometimes result in a dead plug.

Best Regards,
Ray @ Raylar

Great info! Thanks Ray.

Read the link . confused ,which plug / 41-983 or 41-993 tried to find some ngk TR55ix and ngk supplers here in the uk cant even find the # listed here ?

Thanks for the replies guys....Found some of the NGK's local and went with those.
Thanks for the gapping tip also Ray. I'm hoping all i have is a fouled or bad plug. Started acting like I got a hold of some bad gas or had some water (would clear up once the motor would build heat or run through a lil bit of fuel) Now its just a soild miss and does'nt clear up.

Thanks again guys.

Old thread but what are the benifits of the .050 gap versus the .060 that mercruiser recommends?

Would like to know also... New 496 HO owner!!

My boat had 75 hours out of 160 total hours, and they felt a little notchy when throttling, and where not even at the sticks for rpms...

swapped new plugs, and both motors came alive, even at the sticks/tacks too. really helped the boat. 7 bucks a peace is what i paid.

Also would like more info here as I have a pooping at wot and hesitation like a mis going on motor has 75 hr,