Where did the interior come from? You're in Canada so I'm guessing Early Birds?

Rich/lean condition can be adjust on the carb if someone knows how. Not many do these days unfortunately. It could definately hurt your engine if it runs too lean ( especially during break in). You could end up with detonation, even if you don't hear it, which will beat the crap out of rod bearings and could eventually basically blow the motor. It's about your air fuel ratio. At least it looks like the heat is pretty evenly distributed between your cylinders so that's something.