Hello everyone -
1986 Suzuki Savage LS650, around 13,000 miles, sitting about 10 years.

Fuel drained, tank off, carb off for cleaning, plug out. I put about 5 to 10 milliliters of 50/50 ATF and acetone in the cylinder and let it soak. On a lift with both wheels off the ground, in fourth gear, I gently turned the rear wheel.
Today, I got more rotation than before and heard a rush of air out of the spark plug hole. But it still stops before a full revolution. I'm not calling it a hard metal stop, but it's a stop and I'm not forcing it.

Also, the crank access plug is seized. I've tried multiple methods and it won't budge. I may have to pull the entire left side cover, but that means lowering the bike off my homemade stand first., drain oil....Not a hateful task, but a step I don't want to take unless necessary.

Thoughts on process and next steps?
Thanks