Got an old Yamaha Moto 4 that I'm having issues with. I got it cheap so problems are expected.

Anyway, the bike smokes A LOT.

It smokes at idle, it smokes at Rev and it smokes at coming down from Revs.

The smoke is white/gray in color, but thick. Don't really notice any weird smell or anything.

I'm not sure it's oil - so I'm trying to troubleshoot and think about other possibilities before I go digging at rings and valves.

My questions I guess boils down to this:

Will an over-oiled air filter cause smoke as described?
Will an improper carburetor setting (Idle and Pilot screw) cause the smoke?

The bike is revving really high at idle, so I know I need to get that figured out regardless.

What I have done so far:

Cleaned and oiled the Air Filter (Over oiled and I used K&N Air Filter Oil Spray)
Took off carburetor and cleaned it up (how the screws got messed up)
Replaced Oil filter and added new oil

When I first got it she wasn't smoking this bad at all, however she was smoking. The Carb was leaking fuel out of the overflow tube which is why I removed it and cleaned it up. Turned out to be a petcock issue .

Since then this thing has been smoking like a chimney and that's not an exaggeration.