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Spark plug gap and plug type 2004 mercruiser 30

"Hello Randy:

I have a 2003


"Hello Randy:

I have a 2003 3.0L MerCrusier and mine cane w/ AC Delco plugs gaped at .045". That is also what is printed on top of my air breather. Funny thing is in my "Offical MerCruiser Factory Service Manual" which is specific to serial number ranges states that .035" gap should be used.

I just replaced my factory plugs gapped at .045", had 148 hrs. on them with new NGK's gapped at .035". My factory plugs looked as if they were not giving me a good complete burn. Checked my new NGK's after 10 hours and they look fantastic as clean as when I put them in. Looks like a good complete bun in the chamber now. Engine runs very well at .035".

Take care,

T."
 
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