As told to me by Massimo Mondino:
Recently we got in a 1964 Ferrari 330 that came from another shop where it was restored. It was suffering from a lack of performance; not performing the way it’s suppose to.., close to it, but just not quite there. So I began to search for the cause. What was holding this engine back?
After checking the distributors making sure the points dwell was right and also that the points were synchronized on my distributor machine, I moved forward to check the spark plug wires. I did a compression test and a leak down finding uneven cylinders. So I went ahead and did a valve adjustment, I found that the valves were too tight. After putting everything back together I set the timing to proper specifications and also removed the top of the carburetors and checked the the floats. I found that the floats were completely out of adjustment. I went ahead and set them to the right specs as well. After everything was reassembled I went for a test drive. Although the car improved a bit it still wasn’t performing as I expected it to. So at that point I decided to remove the carburetors because although they did look like they were (new) fully rebuilt, after finding the other miscellaneous problems on the car, I just had the feeling that something was still wrong between the carbs and the intake, maybe an uneven carburetor base, or too much free play in the shafts which I know from experience, that in the DCZs are a common problem. I went ahead and removed the carburetors completely placing them upside down on the bench, I checked one carburetor at a time for free play on the shaft and using a straight edge, checked the carburetor base to see if it was warped. When I got to the number 3 carburetor I noticed that when I would fully open the throttle the secondary shaft driven by gear, was loose and intermittently, would only open partially and when it did it was never the same. It would open every time at a different degree/angle. Basically the car was running with 12 cylinders and sometimes only with 10 and some. A simple loose clamp was the culprit that created this extremely frustrating, time consuming and hard to find problem.
Moral of the story? In my line of business when it comes down to particular repairs, like a carburetor rebuild, you make sure that when you start putting it together you finish the job, you don’t walk away in the middle of it. It is too easy to forget a really important technicality. Attention to detail is essential in this business. The clamps forgotten by the last mechanic, not only affected the performance of the car but caused concerns for both the customer (prompting them to take it to another shop) and for me, in trying to track down the problem they left behind.”