Recently I was changing my oil and filter. When it came time to pull the filter I removed the wrong thig. It looks like the filter thing but it's on the left side of the engine. I think there were a few springs and a gasket. Held on by four bolts. Anyway, as soon as I relized my mistake (brain-fart) I reassembled it. This was a couple months ago and no probs yet....So what is it???

I believe you are talking the starter. Is it located to the rear of the engine case and on top?

I guess if it's part of the engine case. It is on the rear and upper part of the left side of the engine.

Sounds to be the starter.
Did you find any oil in there? ;)

Ha, Ha. Nope, no oil. :D