Bought a badly modded (carb pods, etc.) 2000 ZR-7 for pretty cheap a while back - it's taken a while for me to get it to stop bogging. I'm an old hand at working on cars, but very new to working on bikes... So I changed the oil for the second time since I've had it. 10w40 (I figured it wouldn't matter if it's "high mileage" - did I screw up?). Now, it won't turn over. Tries to start. Any help anyone can give me?