Get to the underside of your tach and check the connections for loose/corrosion. If thats good, check the wiring on the engine. Start with this and if still not fixed, repost.
The wires to the tach and clean and tight, the tach wire to the throttle box plug appears to be good, (I unplugged that a few times) there is a lot of wires under the switch box on the motor, which one is for the tach
I found that the tach wire is the gray wire I am tracing it backwards to the motor but the wire bundle plugs into the switchbox, and that is a scary looking thing. I know the tach wire connects to a rectifier or a voltage regulator, do not know which is on this motor or where are they located.
I carefully opened the cover on the switch box, WOW there is a lot of wires in there, Anyway I have a voltage regulator. The regulator shows signs of burning and cracking of the clear plastic cover, I put the cover back on
We started the engine and it runs fine. We measured the voltage across the battery poles and it was same with the engine off and with the engine running, I guess that means the evidence of overheating on the regulator means that is is shot.
What can cause a voltage regulator to go bad like that?????
Will it hurt anything to go and run the motor with a bad voltage regulator??
Just found a guy on eBay that has a bunch of NOS mercury voltage regulators for only 48 bucks with free shipping, he claims to have a bunch of them. Same part number as the one on my motor
Just installed my 48 dollar eBay voltage regulator and now my tach is working and my battery is getting a charge. The old regulator was so burned that the clear plastic cover had actually cracked open
