stillcrazy26

My Used boat, with a 5.0 MPI Merc engine, has only 101.9 hours on the Meter. I pulled some plugs to "read" them because of suspect fuel. I was suprised to see their condition. These "Iridium" plugs have a small wire center electrode compared to what I am used to seeing. It was worn away almost to a point. Is this normal ? The gap had increased from the suggested 0.035" to 0.060". I know that the electronic ignitions use a greater gap but not knowing if they had originally been set to 0.060" or did they wear that much in only 100 hours ? Does anyone have experience with these plugs? I'm "Old school" and looking for info.
The engine runs good without problems but Eletronic ignition can cover up small problems until they are catastrophic.
What would cause this much wear if it is not normal ?
Walt with wear

FIXX

iTrader: (2)

i thought its .045.. .015 is not bad for 100 hours of use..it you are going to replace them do not try and gap them or you will brake the electrode..

stillcrazy26

I did some more research and found a Mercruiser Bull on Spark plugs. Most confusing but from what I gather 2006 was the break point. Prior to 2006 the gap for the same plug was 0.045" and after, it was 0.060". Exception was Carb engine 0.045.
I can see where the general info published on a spark plug chart picked up 0.045 for a 2004 application.
As far as wear, 3000 rpm might equal 45-60mph in a car, x100 hours=6000 miles ?? So if a boats average RPM is 3000 ? not much wear