Tach Setting For a Stinger 75hp

[hoodooguru]

Hi
I have Mercury Quicksilver gauges in my boat and I run a Johnson Stinger 75hp motor.
What does the pulse setting need to be on the tacho?
It worked when first installed now it is permanently stopped on 1500 rpm. I'm thinkin we have it on the wrong pulse setting.
Cheers
Jon

[mcyama]

hey man, your stinger has a 12 pole alt. If it worked before dont change the setting instead check the rectifier for output. Simple way is to start unit then while running remove the positive battery wire form the battery then touch battery with wire again did you see a small spark? if you did rectifier is good if not chance of it being bad is 25% could be stator coil and or wire linking everything together(gray) make sure tach has good ground and has 12volts going to it. happy holidays Martin