Wow! I did this post almost two months ago.
When I removed the carburetor it had a gasket on top of the insulator.
The gasket had the four notches in it but they did not line up with the notch in the spacer.
This blocked off the vacuum port for the power piston.
The gasket in the rebuild kit was the same way. I installed the carburetor on top of the spacer with no gasket like the book said.
After several attempts at trying to tune the carburetor I suspected that I had a vacuum leak around the spacer.
I finally took the spacer down to NAPA and found a gasket that had notches that matched the spacer.
It was actually two gaskets stapled together, just like the book said.
I removed the staples and put one gasket on the bottom of the spacer and one on top and reinstalled the carburetor.
A check with a vacuum gauge confirmed that I was leaking around the insulator.
Then I checked to see if the power piston was working.
This is easily done by removing the vacuum line from the vacuum port on the manifold.
The engine will momentarily speed up and then start to stumble from the vacuum loss.
Place your finger over the vacuum port to block off the leak until the engine idles smooth.
Then remove your finger and see if the engine speed increases again. It should be a substantial increase in speed.
