Thanks hondaman. Is that your plenum.
I don’t even know what the original configuration looks like so don’t know what all else I’d need and I am leery of making radical changes and introducing other issues since I don’t have your understanding of the system. Could the pods cause this with the original pilot jets.
That's not mine: if I had one I'd post it in our own For Sale section, and cheaper! I'd rather help us out than make lots of $ on it.
I might suggest this, as the bike is 50 years old:
1. Make sure those rubber hoses between the carbs and their intake pipes (manifolds) to the head are in good shape, not cracked or such. Most of these are OK unless someone often removed and reinstalled them, then they tend to be hard enough that they leak vacuum.
2. Think about replacing the O-rings in those manifolds where they bolt to the head. They are also 50 years old and hard as plastic now, so they don't seal for beans - especially if they have been recently unbolted: they are the same size as the O-rings in the valve caps above them. If you need some, PM me: I have about 100 of them.
The PD42C carbs (if that's what yours has) use a 12.5mm float bowl level to help enrich the cold-start situation with otherwise fairly lean jetting. If you have opportunity, maybe check this because it is often confused with the 1977 carbs and their 14.5mm float bowl level: while that would let the bike run hot just fine, it would also make the bike harder to cold-start. This makes little difference to the hot-run performance (until about 7000 RPM, then it matters more), which kind of sounds like your description above?
And, about sparkplugs: if they are black, get new ones. Once they get carbon-fouled they will do things that don't make sense according to adjustments you might make. That bike should have the D7EA (NGK) or the X22ES-U (ND) plugs.
