1980 Vanagon - Troubleshooting a well running engine

[Amskeptic]

What is vacuum retard?

If you have the fat can with two nipples coming off of it, you have the dual advance unit with vacuum retard. If you pull the hose off the bigger nipple (the one facing the distributor cap) on an idling engine, you should hear the idle spring up and go back down when you reattach the hose. This is designed-in inefficiency to get as much air flow through the idling engine as possible (the dilution helps reduce emissions and the heat generated helps clean up the exhaust). I have seen a couple of single advance units that were retard only, I think they were California automatics, the tip-off is any timing spec that says ATDC as opposed to the more usual BTDC. With retarded timing, you can expect low vacuum readings.

The most common cause for low power in a Vanagon is camshaft lobe/lifter flattening.

So are you saying that flattened lobes or dished lifters could be why I am missing my topend?

Yes. Met a fellow traveller last summer whose Vanagon had JUST been rebuilt three days earlier. What a dog. A hotdog actually. We went through the whole tune-up deal, and I begged off with his promise to drive directly back to L.A. slowly and dump it at the rebuilder's door. Got an email. Lifter had torn up due to lousy metallurgy.

Vanagons with low power can also have receding valve seats.

Wouldn't I have noticed this when I had the heads offfor inspection?

Um, I don't know. Can be subtle. Who cares? Check the installed height of your valve stems.

Which goes one full tooth counter clockwise? The wiper arm or the black disk?
To keep it simple, am I tightening the spring or loosening?

Neither. You are staying away from the black plastic wheel (I call it the dynamic adjustment which changes the slope of your fuel mixture map.
Just move the wiper arm in relation to the flap. This will move the entire fuel map up in an instant. It is a powerful adjustment so mark your initial spot carefully and go just one tooth (very small teeth on the wiper adjustment). Later, when you tell me it spews black smoke at highway speed with 12 mpg, but idles beautifully, we can flatten the fuel mixture map with the dynamic adjustment

[dingo]

flatten the fuel mixture map with the dynamic adjustment

what adjustment are you referrring to here ???