Hey everyone. New to the forum and just got my 2007 Harley Nightster. I just replaced the battery and there's a slight hesitation when first starting up. When I'm riding everything is fine but sometimes while stopped at intersections the battery light and check engine light come on. When I pull away and get up to speed both lights go out. Any thoughts?

 

You need to have your charging system (stator and regulator) checked. The battery light and check engine light coming on indicates a low or loss of charging voltage.

07's are also notorious for corrosion problems in the relay/fuse block area, caused by water intrusion. Pull all of the relays and fuses, clean the contacts on all of them and then coat the contacts with di-electric grease and reinstall. You can get the grease at any auto parts store.