Lean or Rich is the question. After many, many adjustments, new carbs, intake elbows, new ignitions, flying without a cowl, and many other changes I still have an engine in a plane that everybody has, that won't run inverted and an engine that runs perfectly in another plane that everybody has and there is no obvious major difference between them.

I checked the spring tension between two carbs. If you lengthen one spring and compress them over a brass tube, both springs compress together at the same point. The only thing that I can see is the lengthened spring has more preload at the compressed length in the carb. This should put more pressure on the popoff and reduce fuel pressure on the low end, hopefully reducing fuel dribble or whatever is happening.

As always if anybody has any ideas please chip in.

Chris