Spark Plug Gurus needed

[Reming870]

2009 5.7 L MPI
Original plugs were iridium gapped at 0.06.
Will any harm be done by crossing to a conventional plug with a tighter gap?

Reasoning: I have been having a moisture problem and I think the small tip of the iridium with the wide gap is creating a spark issue at start-up. If I pull the plug after sitting for a few days it has moisture build up. I am hoping with the larger surface area of a conventional plug and a tighter gap may eliminate the problem. I am just not convinced that I will not create an another issue.

 

[Bt Doctur]

Your looking at the wrong end of the horse
Find and fix the moisture leak.,It has nothing to do with spark plugs

 

[Volphin]

Yep, plugs are not the problem. As a rule, the Delcos do just fine if ya want to change them.

 

[H20Rat]

2009 5.7 L MPI
Original plugs were iridium gapped at 0.06.

99% of the time, if you look at a gapped iridium plug, the person has broke the iridium tip off. Generally, you NEVER want to gap iridium plugs.

 

[MikDee]

Try AC-MR43T plugs for standard reach 3/8", AC-MR43TS plugs for long reach, or MR44's, MR45's for a hotter plug, if needed these have a hugh center electrode, and are alloy plugs (no rust), not cheaply plated.

 

[achris]

Prior to using the iridium plugs, the spec for a 5.7MPI was an NGK BPR6EFS or AC MR43LTS. These should work in that engine, but you do need to find out why you're getting water in the cylinders. If you don't solve that, it could cost you the engine...

Chris...

 

[Reming870]

I just wrote off the moisture as condensation. I usually shut down in the afternoon and then store it on a trailer for a week or so before using again.

What else would cause the moisture on the plug? Exhaust riser crack? It is not antifreeze on the plug, I gave it a taste test.

What would the gap be with the ACMR43T plug?

 

[Bt Doctur]

If the moisture is present on the 2 middle plugs and not the end plugs then suspect leaking risers

 

[Volphin]

Platinum or iridium plugs in an engine without catalysts (marine) are an un-necessary expense. Platinum plugs like to run HOT and LEAN. Our non-catalyst engines run relatively COOL and RICH. Save some money and use the MR43LTS plugs in that engine gapped to .045

 

[Outsider]

Hot and lean = clean. Cool and rich = fouled. I have over 200 hours on a set of iridiums, 85% below 1000k, never had a plug problem ...

 

[NHGuy]

t's an MPI motor so it won't get very rich.