I have a couple questions. My first one is about crankcase oil, I heard that 10w-30 is what I should run and I was also wondering if you mixed different wieghts such as 10w-40 what might happen? I ask this because I don't know what the pervious owner put in it. My second question is how you adjust your air to fuel mixture because I took out my spark plug and the prong was black like it's running rich but she still kicks over fine. My last question is that, I have a full DG exhaust and I was just wondering what the general census is? Thanks