I am operating a DA-100 on a Comp Arf 2.6 and my midrange is really rich. I usually fly around half throttle and the bottom of my plane is really "wet" from exhaust. I just switched to Amsoil mixing 80 - 1 but was still rich at mid range when I was running Lawn Boy 50-1. I adjusted the low end until it was "sagging" on throttle up and backed off about an 1/8 turn. High end did the same. I am getting about 6300rpm on a 28x10 Mejzlik prop, 1900 Duralite battery for ignition. I don't have a hole in front of the cowl for the carb and I have about 3/4in between bottom of carb and cowl. I know DA suggests an inch. Do you think if I cut an air hole below the carb, my mid range will be better? Or is there something else I am missing.

Thanks guys,

TJ

I found that leaning out the top end significantly improved the mid range burble. I still don't have any overheating issues. A friend tuned his engine by leaning the low needle until the engine sags with throttle application after startup. He says when the engine gets to operating temperature, it is a nearly perfect mixture, and his engine does run very well. I think backing off the low needle by 1/8 turn is too much; it is a pretty sensitive needle.

I agree. Put the low end needle right at the point to where it sags a little after start up b.c after the engine gets warmed up you will have a great transition and if you high end is just to the rich side of peak, you shouldn't have any midrange problems. When you tune the high end, do it after the engine is heated up, if not you will more likely be making it too rich.

Thanks guys, will try your suggestions