How to hook a tach up to a mid 70s starflight 85 hp

[evinrude bayliner]

I need to hook up a tach to my starflight 85 hp outboard. Is there any info for this?

 

[jtexas]

Re: How to hook a tach up to a mid 70s starflight 85 hp

if "mid-70s" is mid enough, this is the wiring scheme:
IGN = purple wire (keyswitch terminal "A")
GND = black wire (keyswitch terminal "M")
SND = gray wire from the wiring harness
Lt = gauge lighting, or running light switch, or purple wire
tach selector = 6p

 

[evinrude bayliner]

Re: How to hook a tach up to a mid 70s starflight 85 hp

Can i hook up the tach lead wire to the negative side of one of the ignition coils? The reason i am asking is because I am unable to find a gray wire coming from the harness under the dash.

 

[HighTrim]

Re: How to hook a tach up to a mid 70s starflight 85 hp

This may also help.

http://ww2.tflx.com/pdf/obtach~1.pdf

http://ww2.tflx.com/PDF/99320.pdf

 

[Lakester]

Re: How to hook a tach up to a mid 70s starflight 85 hp

Can i hook up the tach lead wire to the negative side of one of the ignition coils? The reason i am asking is because I am unable to find a gray wire coming from the harness under the dash.

---------

hello,

ck for the gray wire coming off the engine electrics. my 71 schematic shows it for mine, both dash and engine... ur's no doubt, too.

regards,
lakester

 

[evinrude bayliner]

Re: How to hook a tach up to a mid 70s starflight 85 hp

There is a gray wire on the harness at the engine but i have not found one under the dash. I should mention that the motor is not original to my boat and wires have been spliced in the past. The boat did not originally have a tach on it. I bought a tach to install on it and on the back of the tach gauge the wiring diagram says to hook up to the negative side of the coil. I would like to know if i can do this with my motor to keep from guessing underneath the dash what wires are what.

 

[patrick4266]

Re: How to hook a tach up to a mid 70s starflight 85 hp

yes