The gen 1 Evinrude E-tec is the finest outboard ever made....IMHO.
Go to barnacle bills Evinrude web site and learn anything a you need to know about these fine motors.
I'm sure your probably fine...have you tried other test like a spark gap measuring tool?
Has the vro been deleted on that model? If not it needs to be.
It won't do pictures right now (technical issues) but you canale a video and post the link. Not that hard to do.
O ring is to keep water out of the end of the crankshaft.
Well your getting a good stream and then your not...that's an odd one.
Usually, good stream but still gets hot. We deal with that one all the time.
Tims original q....was there missing pieces to your impeller when you first examined the water pump?