I have a 1997 Johnson Fast Strike 175 HP. It was starting fine, but by the time I get back from parking my car it shutts off. It starts again, but cuts off several times while I'm underway. It will start back up, but cut off. After about 20 minutes of this it will run fine the rest of the day, but still cut out once in a while. I've taken it to two different dealers. The first said the ignitiion was bad, replaced it and it ran good for 1 day and started the same thing over again. Then he said it could be the ignition sensor. I took it to another dealer and he said that it was the wiring from the ignition to the engine, then he said the new ignition could be bad, then he said that the problem was the powerpack. Help me out......please