Bike feels very unbalanced and sways back and forth... = (

[undercoverbs]

Hi all...just my second post here I think. I live in China and have a gn250... basically the same bike as the gz250, but a little different.

My problem is that suddenly the bike feels very unbalanced. At slow speeds, its difficult to go in an exact straight line. At high speeds, it tilts back and forth, left to right.

I thought I had a flat tire even though it didn't appear flat, so I had air added. Feels exactly the same. There are no screws out of place, so I have no idea what's causing this condition.

Any ideas!?