ORIGINAL: skysfallin
I have the yellow and black color scheme and was very disappointed in this plane when first flying it. CG in the manual is wrong. the plane was very tail heavy and the first flight, as another person with the same problem put it, was like wrestling a tiger with a tooth ache. I thought the first flight would be the last but I did get it landed unharmed. the first engine was an OS91FX which flew the plane ok but will not hover the plane. Then installed an OS120AX, what a difference. Moved the battery around everywhere from under the fuel tank to under the rudder cables where it is now. The thrust angle was off to because the plane would climb when power was reduced on landing. So that issue had to be corrected as well. All in all the plane flies good now and is a good looking plane but I've never had to do so many adjustments and changes on an ARF to make it fly right. If your building one make sure your first flight is nose heavy then make adjustments from there.
I am flying the yellow and blue one. Just maidened it last week. Had it for months on the shelf so decided to build it. With my OS 120 Four Stroke Pumped, the CG is 5.5 inch ( good point to start ) from the leading edge of the wing at the fuselage. Futaba 3010 servos. Spektrum DX7. It was nose heavy with the 120 so I have to place the 6V NiMh battery beneath the rudder cable plastic sleeves and the onboard glow driver battery on the CG. Adjusted the 6V battery until the Yak was slightly nose heavy with an empty tank. Flew it with a Master Aiscrew K Series 15 X 8 prop. Just didn't wring out the Yak much except for a few circuits and some verticals as it was an overcast day. Flew perfectly out of the box, no trimmings needed. Throws set were the recommended for first flight. Landing was a non event, much like a trainer. The weather over here still sucks so looking forward to the next best day to tear up the skies !