I've been noticing a knocking sound from the engine lately. 240 hours on the machine and this noise seems to have picked up over the past 10 hours or so. Without another Mitsubishi s4s engine to compare the sound to, I'm not sure if it's normal or in my head.

Attached is a video taken last night. I know it's hard to hear from video but if anyone can chime in with advice it would be appreciated.