Hey guys, I have recently done engine rebuild on my SWM500r RS 2016 which had 230hrs. The crankshaft main bearing got exploded by surprise. I have changed all the bearings except rod bearing, new oil pump, new cylinder and piston with rings. After reassembling the engine it was running very well for about 10-15 hours. When it is cold everything is fine, but I noticed that when the engine gets warm I can hear strange sound that occurs in the head, I cannot explain, but it seems like knocking sound. I did proper engine break in procedure and did frequent oil changes 3 times during that period. Valve pads are fine, cam tensioner as well. What could cause this sound coming from the head? I leave video link for you. Thank you so much guys for your time and opinions. View: https://youtu.be/vS0Pt4b030k
The engine is already dead. It was a crank rod bearing, which was causing that sound because piston was hitting exhaust valves and eventually it just died. Small debris went through all the engine and cylinder, piston got damaged. So if you notice sometimes small debris that stick to drain plug magnet in short period after oil change be aware maybe of bad bearing somewhere. Be safe and love your bikes guys!
