Rebuilt 318 install problem

Oh I also have a funny story to share:
I once in charge of technical service and warranty for an outdoor power equipment company.
This guy who had purchased one of our machines called me just raising hell and hating everything about our company and the machine. I got him calmed down and told him I was here to help.
The small engine he was having trouble with would no longer start.
I said: okay sir take the spark plug out. What does it look like ? Black, grey, white wet?
He said it was grey and dry. I ask him to check the spark giving instructions on how to do so. He said it had a nice blue spark. I had him put the plug back in. I now ask him to check the bottom of the tank for obstructions by taking the cap off and attempting to see the bottom of the tank. He sat the phone down. I heard him take the cap off waited a moment and heard him say “Oh sh$& !”
He picked up the phone and said “never mind”. He had been trying to pull start that engine for two hours with no gas in it.
Always check the simple things first. Troubleshoot, troubleshoot, troubleshoot!