There are a lot of things that can cause an engine to die at low throttle, but I doubt that low oil content is one of them. You never mentioned what engine you are running, but from the pics it is obviously a fairly tightly cowled two-stroke, which doesn't exactly point to cold running either. But a hotter plug is usually a good idea in the larger two-strokes, so that is a good place to start.

Check for foreign matter in the carb. You are using a fuel filter aren't you? If that is OK, adjust the idle mixture. If that doesn't do it, check for air leaks in the carb or fuel system.

Jim