Guide to Mercury Outboard Tachometer Fittment over the years ....

[Holiday16/85]

I'm a new member on this site, and recently started a restoration of a mid-70's StarCraft with a Mercury 850 2 Stroke engine. Seems there is a lot of controversy as to what Tachometers will work with what engines during that time period. Seems 75-76 was the 'cross-over' years to a more advanced electronics system, and that necessitated different tachometers. It would be very helpful if one of our members (or multiple members) put together a sort of 'Guide' for the 70's Mercury electronics systems, and the tachometers that each required. I am 'knee-deep' in trying to figure out my own situation right now, and from what I read, it's an ongoing concern for many of our older boat owners. I have the MerCruise control with the female plug in the front for a 3 Blade tach plug. This was very popular for many years, but again is confusing as to what tachometer will work with it. Thanks for whatever help you folks that have 'been there' / 'done that' can offer. Holiday16/85

 

[Holiday16/85]

BTW ... I am both 'older' and a 'boat owner' ... but I meant older boats. lol!

 

[Chris1956]

Holiday, Merc motors from about 1970 to present can use the same aftermarket tachometers, as these are driven off the stator. There were also some older Mercury-specific Tachometers that were driven off the switchboxes of battery-powered CDI ignitions.

I cannot comment on pre- Battery-powered CDI tachometers, as that was before my time.