Small Engines (Lawn Mowers, etc.): mtd push mower oil leak at bottom

Question
I have a 22" Bolens  push mower 6.5 hp. I noticed oil under it when I moved it, raised the mower up and the bottom of I guess the motor  and blade are greasy ,checked the oil it is very black. what is my problem and how to fix it, the mower runs great , just the oil leak when parked,
   thank you,
     Linda

Answer
It may be the lower main seal leaking.  You should check for sure and see if anything, like fishing line or string, is wrapped about the crankshaft and seal area.

To check, DIS-CONNECT the spark plug wire FIRST.  Tilt the mower so the spark plug is facing UP, towards the sky.  Now you should be able to safely check to see if the seal is leaking.

If so, the seal will need to be replaced.  It's not that hard but you need a couple of special tools to remove and install.  I have a homemade tool to puncture and remove the seal and a piece of PVC pipe with a cap to install a new seal.

BEFORE removing measure how far the old seal sits inside the engine block.  Too deep or too shallow can cause a new seal to leak.

It is very important to clean and sand the crankshaft before installing a new seal.  The shaft needs to be shiny and smooth.  Once the shaft is prepped carefully slide seal onto the crankshaft and use the PVC tool to install the new seal.

Have you checked You Tube for videos?
http://www.youtube.com/watch?v=mM96NYZzVrs

Eric