G.R. Patterson III wrote:

The primers on the two aircraft I have owned both were slow to fill.

I think this is the same experience I am having. In the training
airplanes, I "primed" by pushing the throttle in and out. I never had to
use the primer knob.

In my own plane, when I pull the primer out, I don't feel resistance
until the 4th or 5th pull of the primer. After that I feel some
resistance.

You should let it run on one for a few seconds (I count 4 when I do a runup).
This lets you make sure that the drop is not excessive. I switch back to
both for a few seconds before changing to the second mag.

I did this for the last 3 flights I took, and didn't notice a drop after
the 50 rpm drop. Generally, when I do this, and there is carbon on the
sparks, I get a dramatic drop. I then go back to both mags, lean it out
til the engine runs rough, let it run for 5 to 10 seconds, and that
clears up my mag check. The mixture is not like a Cessna where I can
"fine tune" it by turning the knob. It is a lever like the throttle
where I push it in or pull it out. I will continue to run the mag check
as you suggested for 4 seconds.

I posted this question as I wanted to be sure I wasn't doing more damage
then good by letting it run longer then needed on one mag.

Allen