Re: 1967 Mercury Merc 60 6hp Sneezing and stalling

[jerry-ahrens]

quote 20mercman:

He was talking about the “Crankcase Halves”, not valves. These cases are split at the crankshaft plane. The flat surfaces can warp, or for what ever reason can have air leakage at the sealing surface. The case is bolted together, and if you look at them, that mating surface is what Jerry was talking about. Carb cleaner, or any other spray that you spray along the seam will plug the leak momentarily and you should see a difference in how the motor runs.

Steve

Exactly.. the engine that I experienced this on was very hard to get started. Once running it actually ran fairly well considering. Here is a ”Hillbilly Fix” that I learned from another buddy of mine: Grab a can of color matched spray paint , (in this case Mercury Phantom Black) and after degreasing and cleaning the surface, paint the leaky seam. Let it dry and give it several coats. If your lucky, the paint may actually seal the leaky joint. I have had success with this on larger outboards that had some tiny leaks. I did it to a 115 Mercury back a few years ago, and it’s still running good. Of course the right thing to do is to take it apart and reseal it, but this can work in a pinch. I have actually heard of some porosity issues on OMC blocks back in the mid 90’s or so, that actually were fixed by painting the powerhead. Pretty wild Huh?