Rotax 914 with CS prop

Nothing stands out in your description, but the devil is in the details.

4.
  BUT if I increase the cruise speed; What Speed?

i.e. first reduce prop pitch to selected higher revs  What RPMs?

and increase power to matching MP,  What MAP?

... This vibration remains even at reduced or increased power settings, and only “resets” when landed and take off again.  Did you also Change the Prop (RPM) setting?  

What is the difference between steps 2 and 3 in your description?

Moreover, reducing power does not increase MP necessarily. Increasing pitch does.

Hi,  Below is a chart of Engine rpm, MP (inchesHg) from the Ritax manual & corerspnding level flight speed that has been determined for each setting.   It also shows fuel consumption (ltr/hr)

So, I climb at 65 kts 115% power - fine.

      Reduce power to say 100% - 154 kts cruise - fine

      Reduce purther to say 65% for 130 kt cruise - fine

      Increase power to 100%, then vibration starts.

The vibration is not severe.but slighltly unpleasant.

Hi,

1. There is no difference between steps 2 & 3 - both reducing power.

2. I understand, but the normal procedure is to adjust power first when reducing power, then rpm

     and prop revs first then power when increasing power - isn't it?

Rgds

re 2: correct, as far as I know.

To increase power, first, increase rpm with the prop control, then increase MP with the throttle.

To decrease power, first, reduce MP with the throttle and then decrease rpm with the prop control.

I have 912ULS so the