Starter motor knocking?

[legendbert]

Can anyone help or advise me please, just purchased 1978 xs650 project, after a little fettling, I managed to kickstart engine into life, sounded sweet with no rattles or smoke, however, the starter motor was disconnected, so I suspected a possible problem, I re connected, then pressed button, motor spun, but as it engaged engine, horrible metallic knocking coming from rear of interior crankcase, this only happens when starter motor engages with engine, motor spins fine when disconnected, and engine runs nice from kickstart, ??

 

[Jim]

Welcome to the forum! Can you put up a video of it?

 

[gggGary]

What side is the noise on? there is a starter reduction gearbox (easily accessed) on far lower left of engine. Then the power path traverse's to the Bendix clutch found in front of the clutch in the RH sidecover. Pretty thorough coverage of all things electric start found here. http://www.xs650.com/threads/xs650-electric-start-system.948/