I have a problem running my Kubota ZG20. I have already spent $500 at two different Kubota dealerships and the problem is still not fixed! Here's what is happening... The engine will try to crank, but the plugs are only getting a spark sometimes. I have tested them and know this to be true. Also, when the mower does crank, as soon as I pull the parking brake up, the mower shuts off. When I try to crank again, the spark plugs will not spark. What do you think is happening? The battery is new. The dealership replaced the seat safety switch and the relay switch. (at least they said they did). Why is the spark plug only getting a spark sometimes? Why will the mower turn off when I pull the parking brake up?