Originally Posted by Thrall
You won't wreck a good impeller by cranking the engine or even starting it up briefly with no water to the engine.
My usual routine if I have to start it out of the water (at home), since I just put a garden hose in the r/w line, is to start the boat with the hose ready to go, then go turn on the hose. It runs for 10-15sec dry, no problem.
I had an unfortunate incident with a defective Perko flush pro first time out a couple years ago. Boat idled for proabably a couple minutes before I realized what was going on. The engine compartment got very hot, light smoke from somewhere was the clue, but it actually did not ruin anything. Exhaust hoses were fine, impeller fine. Not that I'm reccomending to do that, but evidence that starting it dry for a few seconds won't hurt anything.
No offense, but just because things came out ok for you at one time does not mean the correct advice given should be that starting dry is fine. Starting dry is what ruins impellers prematurely, there's really no disputing that. Impellers can go bye bye in as little as a few seconds, it's just not worth a dry start.