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Spark plugs for a 454
Posted: Apr 14th, '19, 10:36
by pschauss
What plugs should I be using? The MR41Ts that the manual recommends have , apparently, been discontinued.
Re: Spark plugs for a 454
Posted: Apr 15th, '19, 21:32
by bob lico
auto parts store cross -reference with Autolite ------done
Re: Spark plugs for a 454
Posted: Apr 27th, '19, 14:04
by pschauss
The plugs in there now are NGK BR6FS which cross references to an MR43T. MR41T cross references to R5673-8 which is a hotter plug with a shorter reach (11 mm vs 11.6). Since the engines ran all right with the BR6FS plugs I will stick with them.
Re: Spark plugs for a 454
Posted: Apr 29th, '19, 09:14
by Rawleigh
Anything but Champion.
Re: Spark plugs for a 454
Posted: Apr 29th, '19, 13:00
by pschauss
Rawleigh wrote:Anything but Champion.
FWIW, I have been putting Champions in my MG and my Healey for 20 + years and never had a problem with them.
Re: Spark plugs for a 454
Posted: Apr 29th, '19, 13:37
by John F.
Reach in important. Make sure you have the right plugs.
Re: Spark plugs for a 454
Posted: Apr 29th, '19, 13:46
by Rawleigh
All I read on old equipment forums is how much trouble people have been having with Champions. Like Bob, I use Autolite for most things, with NGK in smaller engines.
Re: Spark plugs for a 454
Posted: Apr 30th, '19, 08:14
by pschauss
I have had my share of electrical and ignition problems with my two British cars but none that I ever traced back to spark plugs. Whatever the case, the plugs that are in my 454s now are NGK BR6FS and they worked fine last summer so that is what I will be replacing them with.
Distributor caps and rotors will be another puzzle. My port engine has a Prestolite distributor and the starboard has, I think, a Mallory. The marina where I dock is a certified Mercruiser shop so I will him tell me what I need and order them from him.
Re: Spark plugs for a 454
Posted: May 1st, '19, 16:19
by Carl
Rawleigh wrote:Anything but Champion.
I second that!
Dad used to blow the porcelain out of them Champions a bit too often on his 440's. Nothing like a red hot smoker in a gas boats engine bay.
He went over to NGK's and that was the end of that.
I had the Champions in mine, used to foul out bad when trolling. Prior steward told me just give it some throttle, after a couple backfires I'd be good to go.
Oh yeah, really! NAH, that just ain't (and I do not mean "is not") gonna fly for me.
Changed over to NGK's and that was the last time I had plugs foul when trolling.
I guess I should say it was the NGK V-Power plugs, not sure if they have others.
Not a huge Champion fan.
Or maybe its just a 440 thing.
You have 440's Raweigh, why aren't you a Champion fan?
Re: Spark plugs for a 454
Posted: May 6th, '19, 14:47
by Rawleigh
I've always been an Autolite 5 or 86 guy myself. Most of my Champion experience is in real old construction or farm equipment. Champions used to be the go to plug, but started having lots of problems with them in points or magneto situations. But I have a friend with a pair of Mercury Optimax and the only plugs that will run well in them are the Champions. Go figure!