5.7EFI & BPR6EFS plug gap

[Strecker25]

The NGK site has the BPR6EFS listed as .031 but the merc manual has that model plug as a valid replacement, just gapped at .045. Seems logical to follow the manual, so should I just regap those plugs to .045 ?

These are 1998 5.7EFI's

 

[Bondo]

so should I just regap those plugs to .045 ?

Ayuh,.... .031 sounds way to tight,....

 

[Strecker25]

I thought so too, the plugs are at the boat and I'll be going down shortly. I guess it's possible NGK's site is wrong

EDIT:
Just found an old thread....http://forums.iboats.com/forum/engi...s-weirdness-resolved-new-information-included

Mentioning a BPR6EFS-11 for .045, but I can't seem to find much on that part # anymore.

 

[Fun Times]

Mentioning a BPR6EFS-11 for .045, but I can't seem to find much on that part # anymore.

From a quick online check I see the -11 at the end of BPR6EFS is of a more iridium type spark plug vs the standard type. Your engine model doesn't really need or call for that design plug and if it did, it would depend on the ignition system design and if you had a carburetor or a later model MPI fuel system. Also the gap would be different too depending on what you had.

Being that you have an EFI system with Vortec (GEN+) design heads, the BPR6EFS long reach plug gapped at .045 is all you really need.
Typically the basic engine information usually found on a sticker near the top of the engine would have the spark plug gap as well.

Here's just some info about the BPR6EFIX-11P plugs,
http://japansparkplugs.com/boutique/...6efix-11p.html

Often times I have noticed that the NGK site is misleading on the marine info it offers.

 

[Strecker25]

Thanks guys, I pulled one of them to compare and aside from the gap being less the BPR6EFS were identical in size to the AC's that were in it. I went ahead and gapped them to .045 (noted in the manual and on the top cover) and replaced all 16. The motors fired right up and idled much smoother.

A side note, I found 3 plugs that were barely finger tight. The dealer we purchased from last year had both motors out pre-purchase for transom assemblies, so I stupidly assumed they would have checked everything. Maybe they loosened themselves sometime last season. . I had always noticed the port motor didn't pull as many revs as the stbd on hole shot, maybe that was our cause. The cap and rotors were in bad shape as well.

 

[NHGuy]

I have always (6 years) used the BR6FS, which is a basic copper core. Change em every 1 or 2 years. They always look great when removed. I think iridium is over kill and more suited to tightly controlled efi car stuff. But they will always fire and well!