Whenever I go into reverse w/ my Lazer Z HP (19 HP Kaw/60 hours) it bogs down/tries to kill (sorta sounds like a combination of both). It doesn't acyually ever kill, but you hear the engine drop considerably. It only happens when I go in reverse. Now if i go into reverse very slowly, it usually doesn't happen (about half as fast as I normally do). It does this on level ground and hills. Seems to do it a little more frequently on hills. I took it to the dealer a week ago, but it would not do it while he rode it after I dropped it off or while I rode it the next day at the dealer's to try to show him, but the next time I mowed with it, it started to happen again. It used to seem to do it a whole lot more on hills so my dealer suggested he change the mercury tilt safety switch, but I said, if it's not doing it for you or me right now, we'll just play it by ear because it may not be neccessary. But now it even does it on level ground. It also hasn't done it at a lower throttle w/out the blades engaged if that helps. Is this a hydro belt slippage problem, possibly? I've heard many here say they have had problems w/ hrdro belt slippage. Are these symptoms for it? If not, What do you guys think? I will take it to my dealer tommorrow, but would like lawnsite members' opinions on it, thanx very much! Any additional information you need before you answer, just ask for it!