912 stumble

Hi,

That's might be related to main gear wheels, too. Try to press brakes shortly after lift off. 

I have met such an effect in one aircraft I'd flown. The vibrations can be felt thought the fuselage giving fake engine vibration feeling.

Stefan.

Is it a true stumble with a loss of rpm or just an odd shake? If you don't lose any power / rpm then balance ALL your wheels. In 25 years I have never had a stock wheel in balance and so I balance all tires now and some are so far out you need 12-20 weights. Average for me is usually 4-8 1/4 oz. weights. It can make a noticable difference.

I'd be surprised if you really had a loss of power / rpm ONLY when the wheel comes off the ground and no other time.