Hi guys! I'm at the end of a honda gxv140 pushmower engine rebuild. This is my first engine rebuild and I'm learning alot. Got it back together but it started smoking from breather hose that connects to air box. I was running it without air box on so that I could adjust governor and choke linkages. Anyway, I checked the oil and it was dark gray almost black in color and smelled burnt. I also lost compression and found out the connecting rod is shattered. I ran this engine on new oil and I had plenty in the crankcase. What did I do wrong? Thanks!