Re: Leaking Crankshaft Seal.

[Don]

Mumbles video is great, but can be confusing when it comes to some of those OMCs with the crazy drain system used in conjunction with the upper seal..Personally, I feel this design is flawed but I guess it must have worked out OK because the engines were reliable.
But, you will always see leakage when performing the test Mumbles shows on one of the OMCs with this crazy system because there is no oring sealing the outer part of the upper bearing to the crankshaft. The vacuum port is there to catch any of the residual oily residue that "blew by" the upper bearing….