SVHO spark plugs at 21hrs

[blacksapphirez]

It had been struggling to get to full rpm when we left the dock(warmed up) few outings. I pulled these out at 21hrs. Looks like running lean? And there appears to be a rust or some thing at the base of the spark plugs. Oil is fine. Previous owner had it 9hrs in 1 year he's had it so that may be the reason...
I put in some LFR7AIX iridium plugs as a replacement. No JAPAN engraving at all and the hash marks are straight vs slanted... anyone have bought the iridium plugs and can verify these characteristics?

 

[zipper]

Can you show the old/new plugs side by side? They should have Japan stamped into the base, with a line under the P.

 

[blacksapphirez]

Just grabbed these from autozone...

These are made in Japan and the hash marks are slanted.. Other ones from Amazon are made in thailand and have LFR7AIX etched on the side.
Not sure if other ones are fake or just difference in manufacturing location. But ill put the real ones in

 

[blacksapphirez]

After the spark plug change, the boat ran much much better. Couldnt believe how nice it ran. Also surprised a boat at 20hrs the spark plugs were causing an issue...