I was wondering if anyone knew which parts were different between the Kawasaki FH541V (17 HP) and FH580V (19 HP) engines? They have the same displacement, 585 cc, and the 17 HP engine develops 99% of the peak torque developed by the 19 HP engine (36.2 vs. 36.6 ft-lbs). I compared the replacement parts list on Kawasaki's website for each engine, and the lists are identical for the same spec numbers. If anyone has experience in the field with both engines (or the other engines which share displacements, the the 675 cc 21 and 23 HP; peak torque of the 21 is 96.5% of the 23), is there a notable preformance difference? Or is the extra price for the higher horsepower engines a waste of money?