I've always had problems cleaning out the blue plug on my Merc 350 under the knock sensor. I just couldn't get to it. The engineers decided to put the trans cooler right under it and it doesn't help matters that my stringers are very tall. I've never been comfortable with the lack of water trickling out. I'm sure it all comes out over an hour or so but I like the plugs to be cleaned out of dirt and scale. I've tried a number of things over the years: coat hanger, small screw driver, bent plyers, etc. Nothing would fit in there. Today I decided to try a number 4 and number 6 nail. The number 6 nail fit and worked perfectly! Gush! and now the plug hole is clear! So just a hint for my fellow Merc owners.
Hint for Mercruiser 350 blue plugs.
- Thread starter Stephen
- Start date