J

JimWoo50

Well Known Member
Just installed a pmag in place of the right slick and so far am very pleased with the easier starting, smoother idle and I think it's a little faster. One issue that I noticed today though was a high frequency vibration at power settings above 2200rpm. I never noticed them before and they're not terribly distracting but I'm curious as to whether the ei could have changed the dynamics between the 0-320 and my metal Sensenich prop? Has anybody else noticed this?

The vibrations were such that it caused the little chain holding my keys to jiggle. Something I never noticed before w/ 2 Slicks. I suppose I could get a bigger chain but that wouldn't fix anything.

Thanks in advance.
 
Can you narrow the conditions? For example, do you notice the vibration at all times above 2200, or only above 2200 at some upper altitude? Does switching advance setting (A or B as I recall) have an effect?
 
B curve

I have not tried the B curve yet. Now that I have made 4 short local flights with the new pmag and cht's have not increased I will go B curve next flight. I did a mag check at high rpm and the vibration continued on both mags. I will recheck the mags and relean next flight also. I will be in the market for a prop balancing also. Hopefully someone near Chicago.
 
Could it be an airframe vibration? See if the vibe is related to airspeed.

Maybe climb at a low airspeed and high power/RPM. Then dive to a high airspeed. Any difference?

Constant speed prop? Which one?
 
New vibe

Any new ideas on this issue yet? I heard of another similar situation today. While on a long cross country (5 1/2 hrs +-) a little over halfway when the vibration occurred only above 2100rpm. I was not in the plane but the new owner was.
 
One of the things that'll catch your attention in the side by side airplanes is that where you place your feet can greatly change the resonance of the floorboards. I spooked myself on a cross country once upon a time, and have had a concerned passenger or two over the years as well.
 
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