[Bob Lincoln]

I didn't know you shouldn't touch them with skin oils. My 1966 Belvedere had a phenolic float, I rebuilt it a few times, luckily the float was dead-on even at 17 years old.

 

[Bob Lincoln]

It wasn't black, it was brown. Maybe not the same material after all?

 

[Bob Lincoln]

Two 1920 Holleys had the same type float. It was sort of a dense styrofoam-type material (not styrofoam, of course, as that would dissolve). Sort of a brown with a faint gray hue. I don't believe they were contaminated, as the carbs were very clean inside, no residue at all. But always good practice to handle parts carefully.

I just looked at a photo at NAPA online of a black phenolic. That was definitely not the OEM material in 1966 or 1972 on the Holley 1920, at least.

The video on this page shows what it looked like. http://www.carburetor-blog.com/?page_id=233

 

[Bob Lincoln]

I've never found specs, but the way to diagnose this is to weigh the float. Above a certain weight, it is to be replaced.

 

[Bob Lincoln]

I wonder if the needle is missing from the carb, or installed backwards on the seat.

Did you measure the fuel pressure? For carbs, should be about 7 psi.

 

[Bob Lincoln]

I think he means, the fuel pump may have a return line, and if it's clogged, fuel pressure could be too high. That would force the needle open and flood the carb bowl.