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

No direct DA60 experience here, but alot of other experience, so I must ask have you double checked your prop balance?, or tried another prop?... What size/brand/etc prop are you running? The prop is the first thing that comes to mind... or even the spinner, just make sure everything is balanced, and the engine is mounted securely and tight as it should be. Just things to double check. From what I know, those smaller twins should be pretty smooth runners.. but you do have something a bit off it sounds like.

A couple of times I have seen a situation where the shoulder of the center spindle nut protrudes just a little bit outside the hub. The spinner backplate gets held up off the hub but on one side only. Creates all sorts of vibration. Also I don't see mention of what brand prop and spinner is bring used. Some of the budget Chinese items may statically balance but not dynamically.

Exactly. Also when checking the prop itself, make sure it's drilled straight and centered in all axis's. Yes, brand of prop and spinner info might help as well, and who might have drilled it, and how was it drilled, jig or otherwise?.. I'm still suspicious of the prop and spinner area.