john2,
You could have a look at the following:
1. Primer Cap to see if the line is horizontal.
2. Check all 'O' rings.
3. Check that diaphragm is sealed with cap.
4. Check governor hose is connected and hole in cap and block is clean.
5. Check for cracks in carby as well as where main jet screws into (it could have crack down stem).
Try this stuff and let us know what you find.
