I've been having trouble starting my power rake for about a week when the engine is cold, otherwise it starts first pull. Today while using it there was an obvious loss of power when I had it engaged. The engine almost seemed like it was going to die. I routinely change filters and oil. Today I took apart the carb and cleaned it out and attempted to adjust it but may have caused more harm than good. My questions: 1. What would cause the hard starting and now the bogging? 2.The motor is B&S 5hp IC engine. On the carb there are 2 adjustment screws. The one on top is a Phillips screw and the one below is a "flat head". Could anyone tell me what each is for and how to set them. I do plan to get a manual soon. Thanks in advance to anyone that can help me on this one..