I really don't have any heartburn with Kohler engines in general. However I do know three dealers, two in the Midwest and one locally, that are Hustler dealers and they will not stock Kohler powered Hustler machines particularly the Courage line of Kohler engines.
As for my local Scag dealer, they have sold many Kohler powered machines and continue to do so with no noticeable increase in servicing or failures with Kohler engines. In the commercial circles, the greatest percentage of operators have Kohler powered Turf Tigers, some operators have 5 or 6 machines and some with very high time engines.
About ten years ago I had a commercial operator with an early Kohler Command powered Turf Tiger stop by in a panic as his engine failed nearby. He had a new spare engine that I was able to quickly change out for him and got him back into business. I tore down the bad engine and found that the oil gallery plug had loosened and blown out causing a total failure of the engine. I called my friend in WI who has his own power equipment business and had been employed at Kohler in the past and he commented that the oil gallery plug wasn't a tight enough fit but Kohler sent out hundreds of engines with this problem, I haven't heard much any more about this problem since, but not many mechs will tear down a failed engine to see what caused the failure, but I have torn some down just to see what may have caused the failure, however I'm a retired mech and don't get beat on by my boss to make dollars!!!!
If HP is a major interest to you deciding which engine option to buy, go for the most HP in a carburetored engine.
My Scag Tiger Cub was B&S powered initially and I repowered it last March with another B&S engine as this was the easiest and cheapest direction to go in. The original engine had compression loss in one cylinder at 500 hours and I just swaped it out with a new engine. The #1 cylinder on the old engine had seriously stuck piston rings, ran fairly well at power, but sneezed at idle which I didn't like, so it went away!!!! #2 cylinder had 145 PSI compression, go figure!!!
Mad Mackie in CT:laughing::biggrin::smile: