My Super Z was cranking perfectly when I had my dealer put a pan gasket on my 28 efi. I also had them go through everything for a 500 hr. service, when I say everything, I do mean everything. I sent him an email with everything listed in detail I wanted done. My dealer called me and said, "the mower is starting fine but there is considerable wear and play in the starter." I said, "well you know what I do in a situation like that." He then said, "I know you too well, that is why a new starter has already been installed." This gets to be the interesting part, I also brought in a special ordered, completely sealed, 350 cold cranking amp (50 higher than other batteries) AC Delco battery. I wanted this battery, just because I wanted it, mine had been excellent but was over three years old, it may have been OK for another year or even two, then again it may not. They did an excellent job on everything, the mower came back looking like new. I had started the mower 3 or 4 times when all of a sudden with this super strong battery and new starter I turned the key and heard a slight starter drag. I thought to myself, that had to be some type of freak happening and want take place again. This happened a couple of more times before I called my dealer and told him what was taking place. I told Chad (my dealer) this would blow the average persons mind, you have a three year old starter, a 3 1/2 year old battery and the mower is cranking perfectly. We put in a new starter, stronger battery, new improved relays and now it attempts to drag. I said, "I spent all that money so when I touch the key; the starter spins as fast as possible, and the engine starts before your eyes can blink." He said, "I know it has to be right, or you want have it, I'll come pick it up and see what is going on." I said, "there is not but a couple of things it could be, the battery is not getting full voltage to the starter, or the starter has a slight defect." My dealer called Kohler and they did not have a clue, he then called Hustler and they said; we have what is called a "hard start kit." He called me and said Hustler had a "hard start kit" on the way and he had no clue as to what it was, he had never heard of one. When something like this happens; I am going to find out what brought a "hard start kit" into existence. I called and talked with a very nice young man at Hustler, I asked him if he was knowledgeable of the "hard start kit", and he told me he was. I said, "what is a hard start kit and why was it brought into existence." He said, "we have some engines that once they become hot and you switch them off it is much harder for the starter to crank them once again." I said, "I can totally understand this because once an engine is hot and switched off on a compression stroke it is much more difficult to turn the engine over." I had a new truck that did this because the starter was too light, I remedied the problem by having a high torque direct drive starter installed (same as used on race cars). I told him this was not a hot mower starting problem, and explained the entire situation. He said, "this does not really make sense and I will need to do some investigating to see if there is something I'm not aware of." I forgot to mention, when Chad took the mower back they had the starter drag about one out of 10 cranking attempts, he had them install another starter and it did the very exact same thing. The mower has not repeated the problem since it was returned with the "hard start kit" installed. I am not going to say anything about the problem being totally remedied until I have used the mower for a period of time. I am actually confused over this entire situation and would like to have an answer if there is one to be humanly found. I always believe there is a logical explanation for any problem produced, but sometimes answers are hard to come by. Anyone experienced anything like this before?