As per the sticky thread on winterization I pulled my spark plugs on my motor to put 5ML of oil in each cylinder...I replaced the spark plugs as I plan to put new plugs in the motor in the spring (boat will be sitting in heated storage for next 4 plus months)....the plugs I pulled out are concerning me as they seem extra dirty.
Some background information in the motor - purchased in March 2019 and had a Mercury factory replacement powerhead installed with 7 hours on the new powerhead when I got boat....that new powerhead now has about 35 hours on it and the bill from Marina that previous owner gave me states injectors/fuel system were cleaned and flowed when powerhead was replaced. I would've have assumed the plugs would be changed when a new powerhead was installed but these look very old to me. Previous owner ran 93 octane and no fuel stabilizers....I run 89 octane or 91 when as that is all that is available as Ethonal free..I also run Don's cocktail in every tank (minus the 150:1 oil mix). I did change fuel filter when I purchased the boat along with a new alternator belt and both were in bad shape which I thought was odd for a new powerhead (motor has 320 hours on it total).
I would like to hear some thoughts from people more knowledgeable than me on how these plugs look....or am I being nitpicky and should just replace?