Here is a short video on how to check for a leaking top crankshaft seal. The video was done on an OMC 18 but it will work on any OMC motor. Leaking Crankshaft Seal On An 18 Horse OMC Motor-cXt6fV6Z5rc_mpeg1video
Here’s how I check for a leaking top crank seal on the 18-20 horse OMC motors. I pour a bit of oil or fuel mix over the seal and turn it over by hand. Any bubbles coming up means it needs a repair. Submitted by Chip Rathbun.
