I have to install a tach so i can find out the rpms on my mariner 30 hp marathon. i bought this digital tach that cabelas sell and it is supoosed to be wrapped around the spark plug wire 4 times and that's it. So i installed it and got 3,500 rpms on idle and when i full throttled the motor it went up to 9,5000 rpms. <br />I think i installed wrong or it does not work. The recom. rpms are 4,500 to 5,500.<br />have you ever used one of these or got a suggestion ?
