I just got back my M18 from rebuild, new long block, and it just sounds like garbage. It was down with a bad governor when I purchased in July. I can really hear a lot of engine noise, not like my Onan. I sent this engine back to rebuilder once already, they tore it all down and couldn"t find anything, said they ran for 2 hours and all seemed o.k. New pistons, rods, rings, gears,valves and crank reground. Are these Kohlers just noisy compared to the Onan? My K181 was as quiet as a lark. I wanted to stay original on this 16G but at this point maybe I should have gone with the Honda.[yuck] Any input? Marty