Dear ExMark, I have few questions about my new 36" tthp. 1. I have noticed a high pitch "dsing" on occasion when the machine is in usage. Upon closer examination, I figure the sound is comming from the pumps belt tentioner that on occasion comes in contact with the pulley. If you look at it from the side, the clearance between the tensioner and the pulley is very small. Is this a flaw in design, or is it normal? Or is this unique only to my machine? 2. The manual blade engage lever. Lately I have noticed it to snap back (disengage the blades). I have checked the belt tension, and its withing the +/- 16th of the indicator, so its not that. The only thing that I have noticed is the shape of a rod that goes up to the lever, perhaps it need to be further bent for adequate leverage beyond the "center point" (if you know what I mean) 3. Is there a "risk" of running the hydro pumps comletely open? What I mean by this is this: The machine was designed to use the pumps with set limits. I understand the limits are there due to ECS grips control, as well as good ballance between the forward and reverse speeds. What I want to know is- is there a risk of damaging the hydro pumps if I udjust the grips to go further down, allowing the pumps to go faster. I dont know if I made myself clear, but for instance- there is a very little play on how far down the pump moves when in reverse possition, because when you squese the handle- there is only so little space you have to squese and thats it. But if you manually move the pump in reverse, then you can see that it WILL go in reverse much faster. Just want to know if its safe. I want to increase the speed of my tthp. Overall, thanks for a great product.