Well... Did you buy it from Kohler? Did you give the folks you bought it from any good info??? Can you turn the flywheel by hand? Did you ask the folks you bought the new starter about this? We all need the model/spec numbers to even to be able to start to help.....
Is your battery good? How do you know it is?
Does it have the right gear on it? There are 3 different ones.
Is it doing the same thing the old one did ?
whats the model# of the engine? its doin the same thing as the old one- did the old one ever work right? some more info on the history of the engine would be helpful.