2000 Harley Davidson XL 1200 C Sportster Custom "mli" Questions

2007 sportster Xl 1200 engine spurter and late engine reaction at 8800 mlies. Don't know to much about the bike history just bought it. The bike after market loud exhaust system. Possibly carb

burnt hole in centre of piston.rear left.engine was rebuilt 600 mlies ago.no water loss,other three cylinders ok faulty piston cast, or too hot of a plug for too long will rusult the same.

1997 Suzuki Intruder 800 when I try to start it there is a loud click and the dash lights go off and won't come back on till I give the bike a little shake then dash comes back on same thing over and ...