Hello. I have a 2001 electric start 610sm. It has been difficult to start since I flattened the battery. I recharged it but the engine would only turn slowly and wouldn't fire. I thought the battery was probably buggered so replaced it. It still churns over quite slowly and makes a grating noise. I cleaned all the earth and positive connections. I have to use the choke when cold, however I have discovered that when the choke is off and the throttle closed, it turns over ok. Opening the choke or throttle slows it down. I found that if I pump the throttle a few times, then turn it over it fires a couple of times, splutters and dies so if do that then qickly pull the choke while it is spluttering and catch it in time it starts. Has anyone any idea what is going on. I serviced the bike recently, oil, filters, valve clearances. Could I have upset something doing that. It used to start first push of the button every time.