Here's the deal, I have a 2000 Lazer Z with the 26 hp EFI, I just put a new battery in it 2 weeks ago. It will start the mower probably 10 ten times or so and then the the battery loses power to where it will not turn the starter over. When it does start, you can cut and operate the mower just fine. Even when the battery is dead, you can jump it , start the mower and it will run fine. I tried the battery out of my other mower and it did the same thing. It sounds to me like the mower isn't charging the battery. I have had this problem with cars but never with a mower. Any help would be appreciated!!