I have a kohler 27 on a badboy mower and have just replaced the head gasket and exhaust gasket on one side. It started fine and it runs fine until it is under load of blades. I have double checked linkage placement and all items that were removed. When I go from full (no load) throttle to idle it hesitates near idle just a bit. Other than that it runs great. I have 12 acres to mow in the AM I need help.