clogged

I just purchased a 1986 Yamaha Vmax all original with 13,500 miles. I had to rebuild the clutch slave and master cylinders before I could ride. There was a mouse nest under the seat and I noticed something coming out of the exhaust that looks like dog food. When I first got it running, it seemed...

I was draining each carb into a jar to see if sediments were in there or dirty fuel. All carbs drain except 1. Backed screw almost all the way and even cycled the fuel pump and nothing still came out. Is this bad? Any ideas?