Tach Trouble

[pelican]

Originally Posted by jwclbi

Hello, I have 1998 225 EFI Mec, trouble is the tach is intermittent. I removed the tach cleaned the connections, no different. Friend of mine has a new one in the box so I installed it with same result. Is there a "sending unit" for lack of a better term, somewhere on this engine. I looked for a couple minutes but couldn't really see much. Any thoughts would be great, thank you.

that motor,it has 2 regulator rectifiers - back of the motor - swap the grey wire with the other rectifier - it's probably the rectifier


grey wire isn't "hot feed" - grey wire is tach signal
purple wire is ignition
black is ground

not uncommon for those to go bad

check charging system - make sure it's working properly

the high output charging systems,they use 2 regulator/rectifiers