The deflector on the DA is just a flat plate. I do have one as you describe that bends over the carb inlet on a 3W120. I did that because the carb inlet is in the airstream also.

I must apologize, my current BME is a 102 and the numbers came from that recollection. I did have a 100 and there is quite a power difference between the two. So, 6500 is probably a good number for the BME 5.8/100.

I set up all my "new" engines by peaking the top end and backing off a couple hundred. Then set the low end to just get good transition when bumping the throttle from idle. Go back and peak the top end and back off a couple hundred. Then re-check the low end.

After eight or ten gallons, I start to peak the top end and just back off 50 to 100 RPM. As it becomes well broken in I will just peak it and watch for heat problems on very hot days.

I direct incoming airflow all my twins (whether they need it or not) because it is easy to do, adds very little weight, and gives me confidence that I will not have any heat problems. I have used 1/32" plywood and 3/16" foam board to make them. Be sure to leave some air passing over the spark plugs and caps because these get hot also.