The new engine may have had dry cylinders from setting idle. Then when it failed to start (due to low compression), the unburned gas will further wash down the cylinder walls, also making the compression too low to fire the mixture.

Try squirting some oil in each cylinder thru the plug holes, and crank it over a few times [with blue coil wire disconnected] to get the oil on the rings and cylinder walls.

Then put the plugs back in, reconnect the coil, and try starting it.