Oops.

Give this a try.

https://drive.google.com/drive/folders/ ... sp=sharing

Here's a screen shot from a parts manual. I have no information beyond this.

I've collected manuals for CB77s and others on Google drive, some of which is 'recent'.

[...]
I've not shared the whole directory before so let me know if there's a permission problem.

I don't know what the going price is for bikes of this era but I doubt it's more than a few thousand for one that is in good condition, works and is licenceable. I'm sure many would agree that taking a bike that doesn't run and isn't clearly all there, from beginning to end will cost a lot of time ...

As far as I know, yes. Here is some documentation. The Owner's Manual (link #4) has the best description.

https://drive.google.com/file/d/1Gh2XI1b7Vyfv2Qao1UsQNMaN4aeOYron/view?usp=drive_link
https://drive.google.com/file/d/1R_WmLWuC3bnfE2dzb4NLtS4xokTC3R2h/view?usp=drive_link
https://drive.google ...

Almost certainly the float valve is leaking. Being new doesn't imply tat it must work, sadly. Maybe there is some small particle holding it open so blowing it out might help. If your old valve was working, why not replace the new one and see what happens?

I didn't get my CB77 into the shed before the snow came but I did get its cover on. The snow is now up to the fuel tank and the tank has a pile about 2' high on top. It too is in the deep freeze. I live in southern Ontario so winters are quite variable. I'm enjoying this one.