OK I know this has probably covered a gazillion times but please.............once more. When you have the engine wide open and you pinch the fuel line and the engine picks up speed, it is too rich? And if it doesn't it's right? We tested an engine at the field and pinched the fuel line and not change occurred. I flew the plane and it started flying slower and slower so I brought it in and it was way hot. Someone commented that you want for the engine to pick up speed so it is running slightly rich.............which is correct?

Thanks guys..............Andy