I have a John Deere GX-75 riding lawn mower with a Kawasaki 9 HP motor. I bought it used a few months ago and now have problem. It starts immediately (electric start) runs fine for about 3 minutes and then dies. No sputtering, it just dies. It is not a fuel issue, I have verified that. When I check the spark plug after it dies, there is not spark there. I have replaced the plug, so that isn't the problem either. I am relatively certain that it is a electrical problem that is not related to any of the safety or cut off switches associated with the blade engagement or seat contact. Probably voltage regulator, coil, etc. that is failing when it heats up. Who knows more than I do? Let me hear from you.