Greetings. I purchased a demo fixed-deck Stander, 52" with the 17 hp Kawasaki. Since I anticipate that this engine will be underpowered for what I will be using it for (I've nearly bogged down the 17 hp engine on my 36" Stander), I would like to swap out the engine for a 23 or 25 hp Kawasaki, and mothball the 17 hp engine for future replacement on the 36". Two questions: (1) Would the swap affect the manufacturer's warranty for the rest of the machine? The only wording I could find in the warranty document which might apply is "The Warranty does not cover any mower that has been altered or modified changing performance or durability." Of course, the larger engines are an option on this model. (2) If I do not swap out the original engine, how is the engine manufacturer's warranty calculated on a demo unit? The mower is over two years old; has the engine's warranty already expired, or does Kawasaki make similar provisions as Wright does for demonstration machine warranties? Thanks.