I took the new HP numbers for each engine right from their sites puppy. The 29 Kohler is still not the equal of the FX850 even though it is fuel injected. The torque numbers are even farther apart.
I'll be glad when the day finally comes where they are all EFI/DFI.
The Kohler 29 efi is listed at 44.3 lbs. of torque, and the FX 850 is listed at 44.6, really no difference. This tells me the engines will be pretty equal in power, the difference will be seen in reaction time to load; which will make the 29 efi feel stronger.
The method (SAE J1940) Kohler uses will allow them 15% less than true hp, this is not to say the engines actual hp will be 15% less, only that it is possible.
I was running a 60" Hustler Super Z with a 25 hp Kawasaki when my new 60" Hustler Super Z with a 27 hp Kohler was delivered. I pulled out of the grass I was cutting when the truck drove up, after swapping out, I went back into the same exact grass I was cutting, with the exact same mower, the only difference being; the new mower had a 27 hp Kohler engine, whereas the year old mower had a 25 hp Kawasaki. The grass I was cutting would cause the governor to react on the Kawasaki, the new 27 hp Kohler never changed sounds. I new immediately the Kohler was definitely showing it was 2 hp stronger, but this was also during the time Kawasaki was using the SAE J1940 hp rating method.
I was cutting with the same 60" Hustler Super Z that had the 27 hp Kohler; when the truck drove up delivering my new 60" Hustler Super Z with a Kohler 28 efi engine. The 28 efi is nothing but the same 27 hp Kohler engine I had previously; that has now been fuel injected. The same; as I could tell a difference in power with the 27 Kohler being stronger than the 25 Kawasaki, I could tell even more difference in the 28 efi feeling considerably more powerful than the previous 27 Kohler I was running.
There was so much difference, I started paying close attention to how the engine reacted in different size grass. I could tell immediately there was not a noticeable difference when the engine required more fuel for extra power, there was no noticeable lag time as seen with a conventional governor. The efi would hold the high end of the engines operating rpms more easily than would the carburetor type engine. This told me the efi was sensing much more quickly its need for fuel, and this in itself caused the added power to feel much smoother in transition.
The Kohler 29 efi should perform as a 31 hp engine by the SAE J1940 rating method due to fuel injection alone, with the worse case scenario being a 15% hp drag, this would bring the efi back into a 26.5 hp range, so close to the FX850 you would never know a difference.
This is why you see the Kohler 29 efi, which in actuality may be rated at 26.5 hp by the SAE J1995 method Kawasaki now uses; being listed at 44.3 lbs. of torque, and the Kawasaki 27 hp FX850V being listed at 44.6 lbs. They will both be pretty equal in power, with the difference showing up in better fuel economy and quicker response time with the fuel injected Kohler.
I own both the carburetor type Kawasaki, as well as the fuel injected Kohler, meaning I have no preference. I am only educating people on the differences, which comes from my hands on experience.