low rpm at high ambient temps

[Wheels]

My Rotax 912 runs great and the take off rpm is 5200 to 5400 unless I am in Lewiston Idaho during a 90 degree afternoon. I barely get 4800 rpm but if Im not heavy on fuel and its just me in the plane, I feel safe enough. Seems that the exhaust stack is pretty sooty these days too. Should I be looking at anything in particular or am I a victim of density altitude?

[Av8r3400]

She's running a little rich. Depending on the situation you could adjust the clips on the needles in the carbs "up" or closer to the end by one notch. This would lean the mixture a bit.

Or you can just leave it knowing that you are off on power and adjust your flying technique accordingly.

[HighWing]

I have flown into Orofino several times. Great name for a town and great location along the river in the deep canyon. It is hard to describe flying along over flat forever countryside then coming on a deep chasm caused by the river and then finding there is another world down there alongside the river - farmland and towns. This is where I test my 1/16" Lexan windshield - diving down at redline to fly the river. Idaho just about has to be flying heaven.

Lowell