Snip!
Running without a prop is a bit risky - overrev can happen suddenly.
Snip!

I don't understand how this is true...The engine has everything attached
that it has when it is installed in a car.  It should run fine with just the
flywheel...adding the PSRU would be similar to turning the clutch and front
half of the tranny...????

Please explain.

Bill Bradburry