Originally Posted by djagusch
I got one with a 31Hp Kawi and it's plenty of power for mowing conditions. Bigger isn't always better or needed. They go 15mph and mow most stuff fine. It's situations that are abnormal when it lowers the rpm and that might just be a good thing to let us know we are doing something not quite right.
People show pics on Lawnsite of going through 1 foot tall grass and such. They didn't do that at full speed and adding more power isn't the answer either. Decks can only discharge so much. At a foot of grass no deck can keep up with it at full speed no matter how much power it has. It's just how many cubic feet of grass can fit in cubic feet of the deck.
More power is not always the answer.
More power is always the answer, it keeps the deck performing to its design capability, and saves fuel by never putting the engine in a governor operating situation. Whereas a lower hp engine will pull more fuel staying under a constant strain in the same cutting scenario. The mowers entire operating system performs better with excess hp that never allows any rpm drop.
I have proven this time and time again. You can put a 27 hp Kohler engine on a 61" deck, and put a 35 hp Vanguard on the same mower, in what the 27 would consider heavy cutting. The governor will call for all the gas that can be put through the 27 hp engine trying to make up for lack of power, whereas the 35 will use less fuel from never being put into a, "call on the governor situation." Too much power is always better than marginal or not enough power, especially with air cooled components. Anytime you hear rpms fall, your engine and hydraulics are not cooling as efficiently.
The 31 Kawasaki is a step above where Hustler was, but not a very big step. The 31 through 35 Vanguard is much stronger than the 31 Kawasaki, you must get into the 999cc 34-37 hp Kawasaki to compare in power to the big block Vanguard or Generac engines. The big block Kawasaki's use much more fuel, and don't feel as strong and responsive; with the governor being called on more often than with the big block Vanguard or Generac engines.
"ROCKETMAN13" just posted on "LawnSite" about purchasing a new 72" deck mower, I am the one that talked him into buying the 32 Vanguard instead of a 37 Kawasaki. He says the 72" deck does not have any problem functioning perfectly with the 32 hp Vanguard, never changes sounds. He was telling me when running the same mower, with the 37 Kawasaki at his dealers operation the governor activated constantly. I told him every time he heard the governor activate, the fuel consumption was rising. He asked me why the big block Kawi was using the governor where the Vanguard would not. I told him it may be the way Kawasaki sets their engines up, and this could be the reason Kawasaki engines use more fuel with no noticeable increase in power.
I was talking with my dealers new Hustler rep this morning. He is the one that mentioned to me what I've posted in the past, that dealers may as well get ready; because it will be an efi mower engine world before long. I said to the rep; Kohler told me they were working as we spoke at putting efi systems in all their engines, and I felt sure Kawasaki was following suit. He said Kohler was making their customers aware; if their mechanics were not familiar with efi technology, they needed to be buying the diagnostic equipment and acquiring the knowledge to maintain them.