My Lazer Z hesitates or loses power when you hit a hard bump. It is a Kohler 27 hp with only 50 hrs on it and it only hesitates for less than a second. Then resumes at full power. The best that Exmark could guess is that I may have a bad safety switch. I by passed the switch on the seat but it still does it. This would be a hard thing for a dealer to track down since it doesn't do it all the time and actually doesn't hurt my mowing its just a little agravating for a new mower. Could it be a carb problem? Or do you think it would be in a safety switch? Any other ideas? I doubt my dealer would ever be able to find it since it only does it every now and then. Its seems like the fuel is shut off for an instant after it hits a bump. All replies welcome. I hate to replace every switch only to find out its something else.