My motor is a 1968 Mercury 500 (50 hp) 4 cylinder serial number 2105127 On my 16' Shellake fiberglass runabout, top speed with all 'un-necessary' gear and land lubbers tossed ashore, top speed was 20 mph. The addition of a first mate dropped the WOT speed to about 13 or 14 mph. The previous mechanic made adjustments to the timing that seem not quite right to me, but the motor did actually run as noted above. After many hours of analysis, carburetor rebuild, endless adjusting, and hopeful observation, I think I know the problem. It appears to me that the seal between the crankcase and the engine block is beginning to fail. A bit of fuel accumulates and the tiniest of bubbles form along the length of the mating surfaces (brown goop) when the motor is (attempting) to be at a pretty fast idle. I think a leak down would confirm, but I think the tiny bubbles tell the whole story. Being a reasonably good mechanic, but not a masochist, here is my question: Can I simply follow the dis-assembly instructions in my Seloc Manual up to the point where the crankcase is removed from the cylinder block, clean the mating surfaces, apply Permatex 2C-12 Sealer, carefully reassemble and... expect to have a good result? That is to say, leave the crank seals, end play, and other items alone... What do you guys advise? v/r Irondogie PS Any suggestions with regard to crankcase to engine block sealer would be appreciated also.
