Lately, my Dyna has been getting harder to start, occasionally kicking back with a whoosing noise out the intake. It starts to turn over, acts like it is not going to make it, then usually rolls over and starts. Occasionally, it does not make it and kicks back as noted. At first, I thought the battery was low/bad. Battery checked out okay. So then I looked for loose/corroded battery cables. Both cables at the battery were clean & tight. The main ground was clean and tight. The positive lead to the battery did have some corrosion under the rubber boot. Removed and cleaned the cable end and reinstalled. Acted a little better for a while, but started gertting worse after a couple of weeks. The cables do not appear to have deteriorated since last checked. Questions: Are there any other cable ends that should be checked (Battery Pos & Neg, main ground to frame, Pos cable to starter). If so, what/where are they? Would timing being advanced too far cause these symptoms? Not sure how it would change, but the kicking back makes me wonder. Could the starter be going bad already? Bike has 15K miles & 2 years. Thanks in advance for any help.