Originally Posted by BobTurner
I had something similar - vibration at lower rpm. IIRC I tracked it down to a metal part of the ramp baffle being a fraction to big - it was touching the cowling instead of the flexible material.
This was it. I trimmed the ramps (including the vertical portions) and went for a flight today. Vibration gone. Dialed it all the way down to 2100 and it was smooth running all the way. What a relief. That vibration has been dogging me since the start.
I must have had the cowl on and off a few dozen times since first flight. And each time I installed, I fought getting the cowl around those inner vertical baffle pieces. Amazing what doesn't compute when you're expecting a problem to be somewhere else. Not only is the vibration gone, but installing the cowl is a lot easier.
Thank you again for taking the time to post.