Only Cub Cadets - 149- changing head gasket

OK, I don't profess to be a cracker jack mechanic, but I know a thing or two about a thing or two. That said, I noticed how the head gasket was leaking on my 149 and decided to do a little additional maintenance on it while I was changing the gasket.....new points, spark plug and wire, hydro fluid and filter. Anyway, just when I thought my work was complete, and as I turned up the throttle on it, the K321 began to shake fairly violently. As it idled down, it again seemed to run fine, but when I went to give it some throttle, it began to shake again. I checked the gap on the points and reset them to .020 and fired it up again. It seemed to run better, but then I noticed smoke coming out the valve breather (?) on the side of the engine. Hmmm. I checked the engine oil and it seemed to have a bit of gasoline smell in it, so I immediately changed it cleaned the valve breather(?) and started it up again. Runs excellent! I adjusted the carb just a bit and it purrs like a kitten now. So...what did I learn? Did gasoline seep into the cylinder and cause it to shake like that? Also, setting the points is a tedious task, at least it is to me, having intermediate level skills, at best. :bash2:
Does any of this sound familiar to any of you? Through it all, I still had fun, and do you know why??? I wasn't at work.....haha.
Thanks for your help.