Originally Posted by puppypaws
Just remember how as of 2014 the rating system was changed..."In the past the standard permits the advertised rated value (the label on the engine) to be 85% of the test values.” For example, on an engine labeled 19 hp, the actual horsepower of the engine could be anywhere from 16 to 19 hp. Under the new revision to SAE J1940 the actual horsepower listed on the motor will be at least 95% of the actual, tested horsepower. In other words, an engine labeled as 19 hp will actually produce 18-19 hp at a certain rpm."
Even under the "old" J1940 rating standard, yes they were allowed 15% which in reality could bring the stamped Kohler 27 down into the 23 hp range legally, but that by no means proves it is only 23 hp. The 27 hp Kohler could in actuality be a 24, 25, or 26 hp engine, just because it states an allowable 15%; this does not mean that percentage is actually met.
Besides that, I've operated both carburetored engines on the same mower and the the 27 hp Kohler would out perform the Kawasaki by a considerable amount.
Kohler is still over rating their engines. all anyone needs to do is check their site and read the specs sheets for each engine. The J1995 rating is always way down at the bottom, and is still at least 1-1.5 hp less than what they are rating them as as of now.
I also know they could be rated to 15% below what they were selling them as. I have kept up with this as much as anyone. I know on top of that, that they were normally at the 15% below level from several sources including JD themselves. JD was making them use the correct rating on the engines they bought from Kohler well before Kohler finally started doing it. Previously rated 23's were now at just about 20, the engine labeled 25 HP Command like I owned only a couple years back was rated 21.9 on the engine label in all following models from 2012 onward etc etc.