[Fot] Spitfire mixture needles

[Mike]

Greg,
    We've had similar problems on many different cars. The stock needles 
don't provide enough fuel. Working with Joe Curto we've been able to 
make most of them run OK by fitting richer needles to the detriment of 
fuel economy.
    I think (unscientific theory with no hard evidence) that the problem 
stems from the changes in gasoline formulations. As the 'quality' of the 
fuel has changed over the years the energy in the fuel has diminished. 
More fuel is needed to get the same performance.
    The problem with this idea is that only about 10% of the cars we 
work on need this type of repair. Most of them run OK with the stock 
setup, although sometimes adjusted as rich as it will go.

Mike Engard