OK, now that I have a path forward on my air filters, I need some guidance on my PHF30 carb float-height adjustment (or not).
I was following the guidance of Greg's teachings, plus some other entries here:http://www.thisoldtractor.com/dellorto_setting_the_float_height_on__carburetors.html
The guidance in Fig 13 of the link does not state this, but I assume the float should be flopped over until it JUST closes the needle valve. The problem I'm having is it's IMPOSSIBLE to determine when this is with the tiny, tiny spring rate on that tiny, tiny spring.
The VHB carbs specify a more typical method, with the carbs upside-down and the float compressing the spring to a calibrated amount.
If I use this upside-down method, the float compresses the spring COMPLETELY, bottoms it out, and the height measures below the specified 18 mm (.709 in).
If I use the Fig 13 method, there is no way I can sense when the needle valve actually makes contact in order to measure the height. One previous poster said to use a small hole attached to that circuit and blow thru it to see when the valve closes. But I still have the problem of holding the float dead-still when that happens and measuring, which seems full of error.
The GOOD thing is the bike WAS running/burning perfectly before I dismantled it, so should I even bother, and just leave well-enough alone?