Since the onset of the cold, it's been really tough to start. Also, it runs pretty sputtery while warming up, occaisionally while riding it. Changing the plug helps for a while (CR8E). But, I've noticed, the plug is always black and has never been the tannish color that 4 strokes should have. Do most people get the tannish plug color? If so, does anyone see anything in my jetting specs that might be causing this problem? If not, what else could I do to get the plug color right?