Proper 454 MAG MPI Spark Plugs

[ShellBack89]

I've got a 1998 Cruisers Yacht 3870 with Mercruiser 454 MAG MPI Inboard Engines, serial numbers 0L005998 & 0L006000. Went to change the spark plugs and have found 3 different NGKs to choose from but not sure which one is correct. The manual states NGK BR6FS for stern drives not inboards (which is currently installed), the Mercruiser Parts website states NGK BR6FZX & the engine plate states NGK BR6FVX. The last two are both Platinum plugs. I spoke to a parts dealer today and they said NGK BR6FZX but don't have any in stock. The BR6FZX are out of stock online as well. The BR6FVX are in stock. The BR6FS were installed by a certified mechanic but since then the engines have had timing issues which is why I wanted to change the plugs as well as a few other tune up items to help get the motors running better. Any advice would help!

 

[alldodge]

serial numbers 0L05998 & 0L006000.

S/N are bogus

 

[alldodge]

98 to 01 plugs are MR43LTS
No platinum, nothing special, regular ole plugs
Champion RV12YC NGK BPR6EFS

If you want to spend money buy the ZX platinum ones

 

[QBhoy]

Hi
although most MPi im used to like the short blocks all take iridium plugs like NGK 5599 or at least ITR4A15 platinum plugs...I have a feeling your older type big block is different but should be platinum at least for later engines, last I read about it. Is it not likely that it would be something like BR6IX or similar ?
also read that BR6FS do older Mpi so not sure.

 

[ShellBack89]

S/N are bogus

No they aren't. I've got the documentation to prove otherwise but thanks for the response.

 

[alldodge]

Change the plugs on initial post, due to inboard they are the LTS models

That said, I plug the S/N in and nothing comes back

 

[ShellBack89]

Change the plugs on initial post, due to inboard they are the LTS models

That said, I plug the S/N in and nothing comes back

 

[ShellBack89]

This picture is from the manual and states BR6FZX

 

[ShellBack89]

[No message]

 

[alldodge]

First post MPI and not Horizon
Post 8 hilight Horizon

0L05998 S/N is not complete, if a zero is added it s a 5.0

If you look at the S/N in the Merc site it does not list 0L0060000 for a 454, only a 8.2

In any case, I'm still think my first post is correct unless there is something else

 

[ShellBack89]

First post MPI and not Horizon
Post 8 hilight Horizon

0L05998 S/N is not complete, if a zero is added it s a 5.0

If you look at the S/N in the Merc site it does not list 0L0060000 for a 454, only a 8.2

In any case, I'm still think my first post is correct unless there is something else

My mistake should have been 0L005998 not 0L05998. The corrected serial number as well as 0L006000 both fall within the 0L002200 thru 0L086049 in a 454 MAG MPI Horizon Gen VI GM 454 V-8.

 

[alldodge]

Your post 8 should clarify