ORIGINAL: kahloq
If its a new 220, the vibrations will settle down once the motor is broke in well. Also, not sure exactly how you mounted it, but using vibration dampening mounts sometimes actually amplifies the problem.
Now, you said it slowed to a crawl with the landing flaps only yes? I wonder how fast you could slow the plane down once the mains touch if you flipped the air brakes on. Since these kinda act like a "crow" setup, it should create a lot of drag. of course, you'd want to test this in the air up high to see what the plane does first. You may end up having to mix in an elevator to airbrake setting if it balloons are loses altitude(more likely it will climb a little if you have the top airbrake set to stock configuration where it doesnt deflect up as much as the lower portion goes down).
Where did you set the CG? Did you think it flew really well at the point, or do you think a different location would be better and why?
I set the ballance at 112mm. I'm pretty satisfied with it thus far with only one flight. The engine is mounted directly to the wood. It slowed well with the flaps on landing, I only tried to land once with the flaps on, never tried without them since I only got in one flight.