While my boat was down after being rear ended last year I had them change my spark plugs and some other stuff while my transom was being worked on. The glass shop does run of the mill maintaince stuff also.

Needless to say they must have cross threaded one spark plug in the cylinder. The cylinder was so messed up the plug wouldn't even come out and my tech (the one who normally does all my wk, not the same place that was fixing my transom and installed the screwed up plug) Was afraid of breaking the plug. While the head was off He showed it to me you can plainly see its crooked. The tech let me try and get it out and i was actually flexing the plug to the point it was going to break

Needless to say i did not want a sleeve or what ever you call em installed so i replaced the head.

Now to the point. I have been running the cocktail since day one. Mind you i have 765 hours on my motor. My cylinders were dang near spotless with no carbon. My tech asked if i was running quick clean in my fuel. He swears by it as well.

So if there are any disbelievers I saw first hand a clean well used motor