i just bought a used boat, it has a 86' evinrude 140. the first time out the water temp at idle was 163 running was 200. this is too high according to the book. i replaced the temp sensor. now the temp won't get over 125 running. i'm wondering about the placement of the sensor, since it just rests aganist the head. it is positoned on the top left corner of the left head. also how accurate is the system.