I Just picked up a used speed 3 ('2004'), no owners manual. Previous owner said you had to run premium. is this true? I ran out the gas he had in it, put mid grade in it, bike ran fine for 60-70 miles. Now it smokes, hesitates just off throttle. I think I may have got some bad gas (no I didn't put diesel in it, I checked the pump the next day). I went to check the oil, but I am not sure if you check it on the side stand or straight up. These should be easy questions, I did some searches on the website but didn't find anything.