Adjust valves

What? your putting the socket on the crank 8 times and watching for the 90* mark 7 times. But hey do it your way, It is JMO!
You might not have the right tools. I have some big stuff, left over from a great uncle who worked on big trucks. So using a long handled 3/4" drive ratchet with a short extension hooked to the socket that fits the crank bolt, it turns easy. With the ratchet, the socket, etc... stays on the crank the whole time. You don't even have to take the plugs out. The socket goes on the crank once. And the best part is if you can follow the chart, there is absolutely no guessing to be done. I think for someone who has never done it before, following the chart is virtually idiot-proof.