Propeller vibration following carburetor synchronization

use better Synch equipment  if you get it to under 2 mm hg  the ballence tube can be blocked off or not it makes no differance to how it runs  some chinese gauges   and eletronic  equipment are not with in under 1 to 2 mm hg accuracy... pay a professional to do it  as often low speed is fine but at 3000 rpm it goes out make it perfect where you fly then it  will be smooth. if not Prop ballance.  wash the buggs off your prop before each flight...   

Thanks Wayne. I got them synchronized perfectly at idle to 5,000 rpm at 1.0mm HG,  just a tad off at .05mm HG and then only above 4,000 rpm, not enough to bother with especially when dealing with loosening, turning, and tightening nuts to make fine adjustments. Anyway when done idle smoothness was much improved over the baseline readings I took prior to starting the synch. The real head scratcher is the vibration that appeared afterwards.  It wasn’t there before the synch, which I performed after noticing a slight roughness at idle, which is now gone after the synch.  The vibration sure feels like the prop, not the engine- it’s a buzz in the rudder pedals at WOT in flight I recognize from my helicopter days. Only there’s no tail rotor on my Zenith 701 :)  I checked the rig (track) of all three blades and all three were spot on. Agree with you on keeping the prop clean, I fly from a grass strip exclusively and wash the windscreen, leading edges of the cowl, wings, tail surfaces, and the prop blades after every flight. Got a nearby A&P who does dynamic blade tracking so I’ll get that done and see what happens. Maybe I’ll ask Santa for a DynaVibe for Christmas this year.

http://balancemasters.com/aircraft.html

Thanks Garrett! I appreciate the responses but I’m more curious as to why the the vibration appeared than how to fix it.  I’m just scratching my my noggin as to how a slightly out of synch 901 can mask a prop imbalance.  Or can it? Therein lies my metaphysical juxtaposition.  

Is the spinner on straight? Checked to see if it wobbles during idle. The reason I put the Balance Master on my plane was the spinner got painted and that was enough to cause vibration. I eventually replaced the spinner with new but left the Balance master on, just in case.

https://www.youtube.com/watch?v=kzcfaNuecgQ