Thanks Deejay - that means we just have an ordinary emissions Pulsa-Jet there, with no mystery beyond why it is running rich. Since it has been established that the air filter is OK and the choke is wide open, it sounds as if it will probably be necessary to remove and open the carburetor to take a look at the main jet. However, a question first: adeas, was the slot on the pilot jet already damaged when you got the mower? If it was, we still need to be on the lookout for foul play by the previous owner. This could include interference with the calibrated holes behind the jet.
