So what went wrong? Kohler ch620.

[SawAddictedFarmer]

Customers horizontal shaft ch620. Was ran with almost no oil just long enough that the hydro lifters collapsed. So maybe 20 seconds. Got the oil changed and the lifters pumped back up and did some other stuff. Cleaned the carb since it was running lean a cleaned a lot of crud off the cylinder fine. A couple laps around the yard mowing and I went to put it away, halfway back to the barn and it starts a horrible banging noise a stalls. A couple tiny metal fragments on one spark plug and some dings in the piston. Going out shortly to pull the heads.

 

[EFSM]

Broken valve?

 

[SawAddictedFarmer]

Yeah this engine is done. Looks like a connecting rod bolt came loose and worked out a quarter inch and then everything detonated. One connecting rod broke and took out the cam shaft and a chunk out of the bottom of both cylinders