The troubleshooting method I have advocated seems way different from anything else you have encountered? This should not surprise you. The usual troubleshooting information, including all those YouTube videos, don't come from folks who actually make a living servicing 1970s Hondas in a retail environment. Nor have the few who claim otherwise done so for more than fifty years, or spent most of their lives in manufacturers' warranty and technical training departments. Choose your expert.

You have also noticed that the official Honda manual (as well as the unofficial ones that mostly echo the original) are absent anything that looks like this method. For that matter, any method at all. And that is their failing. No systematic approach. This was not always so. In the 1960s, Honda's manuals were fairly technical, not like now. And the troubleshooting methodology in them looked a lot like what I have recommended. Reasons for this are many but the main one is that today's legal landscape has forced manufacturers to change their manuals from something that aided maintenance to a completely different thing that helps them defend lawsuits. Welcome to uber-consumerism.

I welcome dialogue.