Recently I saw a new Kohler v-twin engine on a zero turn with the oil pan off. Was surprised to see a plastic cam gear and plastic governor gear which had broken. It was a new machine. I've always liked Kohler engines but I won't buy an engine with plastic gears. The new Toro commercial v-twins have plastic cam gears. The new Briggs Commercial Turf does Not have plastic gears in it. Not sure about Kawasaki but don't think so.