Exaust now has a heavy smell all of a sudden when before it didn't.

I noticed that all of a sudden I'm having a obnoxious smell coming from my exaust when before I never had a smell. Bike still runs fine but that smell is odd. I was wondering what it could be. I thought my exaust was loose (the main top bolt fell off once without my noticing and later that day I put a new one. ) So I thought that maybe the stress on the pipe made it leak out before it got the muffler but even the smoke coming directly from the muffler also smells like that so I don't think my catalytic converter is bad I think. Perhaps spark plug is going? Thoughts?

I guess Winter has arrived in Pennsylvania ? I also guess you notice this more when the engine is cold ? If so don't worry about it bud, its just the fuel enrichment device (choke) working as it should.

Ah, ok yes it is now winter. The first colder weather kicked in. And the smell does go away after my engine warms up. Thanks for clarifying that.

Another possibility to consider.
A long ago in a land far away I used to keep my bike in a friends garage. He had a cat. The cat took a leak on my bike. The first I knew of this was when I stopped and the exhaust had heated up.

Gasoline companies change the fuel composition at the start of winter and summer. Maybe that coupled with the automatic choke causes that particular smell. Just my 2¢