I have a new 2004 HP 23 Kawasaki/ 52 deck. I put about 6 hours on the machine and it cuts and vacs with little effort. Despite this it does not seem to be working at full power at max throttle (with or without the ultravac attached). I sense theres more power than I have access to. The throttle moves smoothly through its range, but the engine response seems to deliver only 3 distinct speeds based on engine noise and performance. Movement of the throttle through the first 1/3 produces only one speed, 2nd 1/3 another, etc. There doesnt seem to be any other variability in the throttle response. Is this normal? And how do I know if the engine is producing its peak power at max throttle? Can the throttle be adjusted easily? The selling dealer is about 15 miles away and not likely to stop by to check the machine.