Checking the oil level on this bike is quite a challenge it seems. I try to hold the bike upright while kneeling down on a knee, but I can never tell if it is perfectly perpendicular to the ground. It looked to be about midway between the upper and lower line when i experienced this shifting into neutral problem.

I have since added just a smidge of oil, and it currently sits (as best I can tell) just under the top line almost touching it. Is that too much?