I have a Mercury 65hp 3 cylinder 1974 model. I bought a Faria tach for it, and when I start the motor, it goes to 0 and wont go above that. When I turn the motor off, it drops back down. So, there is a little movement when I start the motor. Can anyone tell me what the pole setting for this motor is? Is there something else I can do to make this tach work?