I am using a new DA60 in an EF 94” MXS, I am having trouble with a violent low end vibration that occurs around 1/4 throttle

when I first went to run the engine it was too lean on the bottom end to fire, I richened it up to get it running then leaned it off to get excellent transition and generally it starts and runs very well

i also moved the ignition right back which has made little to no difference

I feel maybe it will improve as the motor breaks in but the vibration is quite severe and is causing unnecessary wear on the airframe, it can be heard when the model is in the air, almost like the engine is “four stroking” but only at a certain low end throttle position

has anybody else had an experience like this? I am 1 turn out on the low needle and fully back on ignition timing

thankyou
joe