I have an EVO 50 that sat for months.....many months. I changed the rear bearing and started flying it again recently.
Right now, on just full collective climbouts it bogs a good bit. I can't remember it ever doing this. It's most likely mixture but I can't seem to sort it out if it is. I have 2 600N's and I don't have any problems tuning them. They will climb forever with more pitch at similar head speeds.
What's in it:
Fairly new Hyper50 w/SB50 (less than 5 gallons thru it), 30% Magnum, RL10 w/1800HS, 600mm V Blades, 92mm plastic tail blades, +/-11* pitch measured with a JR pitch gauge. Everything moves free with no binding or excess friction.
I can't figure out wether it's my set up, mixture, or too much pitch. All I did was change the rear bearing after it sat for a long time and I don't remember it doing this before I sat it up. The engine starts, idles, and runs well but it just may be too rich.