While mowing the lawn with my Sears Craftsman Eager-1 self-propelled lawnmower, model # 917.377561, I noticed the engine and mower deck becoming drenched in motor oil. The leak was so bad it almost looked like the engine block had cracked, but that was not the case. After checking further I noticed that the oil was coming from under the flywheel. The engine manufacturer for this particular engine is Tecumseh and they sometimes add an oil breather to the Eager-1 engines and that was the cause of the oil leak.
In this case the rubber breather had shrunk allowing oil to escape around the edges of the breather and on to the mower deck. It was easy to tell that the breather wasn't sealing properly because it was lose in it's mounting hole where it should have been making a tight seal. The only fix is to replace the breather, a $17.00 part.
Eager-1 Engine With Breather Removed
The breather for the Eager-1 mower is Tecumseh part# 36557
New Breather Installed
Once you have the flywheel off of your Eager-1 engine all you have to do is pull out the old breather and insert the new one. You will need to cut the tube that goes to the carburetor to the correct length before you replace the flywheel.
