First day of lawn season, cut the lawn after a difficult start. The next day put a new air-filter, fuel-filter and spark plug. Looked under tractor and found a puddle of oil. Pulled dipstick and it was empty. The main pulley was completely full of oil. Any ideas?

Do not restart this engine. You have a main bearing and oil seal on the bottom of the engine, it has failed. You need to tell us if you can handle pulling the engine and bearing or will you need to give the job to a shop.

Thank you for the answer. I will need a shop to do it.

Very helpful

If I decide to do the work myself, how big of a job is it?

Hi,
You must disconnect the double-stack sheave, the deck belt, engage the parking brake to release the drive belt, pull the four bolts holding the engine on, disconnect there wiring and cables. Flip the engine upside-down and remove the sump. Pry the seal out and replace it. I think that for whatever reason it failed that the seal is your problem.
Peace,
Clarke

A trick that works well for replacing these kind of seals is to drill two small holes opposite each other into the seal and insert a sheet metal screw part way. You can then grab the head with a pair of vise grips and pull.

Works for the rear main seal in a car.

Thank you Clarke & KISS.

So, do you think your going to tackle it?

Exploded diagrams should be available on Small Engines, Lawn Mower Engines and Generators by Briggs & Stratton (http://www.briggsandstratton.com). You'll need model, type and code stamped on the blower housing. You have to pay for service manuals, but the parts breakdown is free.