1975 Evinrude 50hp with faria tachometer question...

My old 50 hp evinrude was rebuilt so i decided to add a faria 6rpm tachometer. couldnt find the grey wire in the harness but did see it on the motor coming off the post were the yellow/grey is so i hooked there. Bought a new rectifier because before had nothing at tach. Now Its working but moves crazy when the motor is idling it moves slowly over to about 4 to 5 sometimes 6rpm. If i floor it it goes down to 2rpm and back up some. Let off the gas and it moves up the rpms. I had a teleflex that would switch to 6p or 5p. I bought this new faria 6p tach and it does the same thing. I hooked the send wire to the grey wire on the motor thats close to the coil packs coming right off the post were all the wires from the harness hook to. Keep in mind this is a 1975 AMF Crestliner Stinger 440. the wireing harness looks to be fairly new and in good condition. The yellow/grey wire from the rectifier screws to the post then a yellow wire from somewere to it and then the grey wire coming from the harness.? If anyone could help i would be very thankful. This is aggravating. lol

Re: 1975 Evinrude 50hp with faria tachometer question...

If I under right then the yellow/yellow gray should go too gather yellow going to rect. yellow/gray comes from stator gray wire from harness goes to gray wire on rect.