I never liked external linkages with scale machines, (although have to bite the bullet on ailerons and flaps) as it "Uglies" them up a lot. Should have seen the trouble I got into fitting everything into the back of the N/P 53" A6M. Ouch!

Yours may just have been too fast a throttle increase and the requirement to keep the tail down for control would cause it to launch before it has enough airspeed. Been caught by that one a few times, mostly when doing maidens on planes new to the field.