TOPIC: Tach help!?!

I have a 63 Sea Ray 800, it came with an Evinrude 75hp Electric shift outboard on it with an Airguide Tach and Speedo. I'm wanting to put a mid 70's Mercury 850 85hp outboard on it. I have heard that some but not all Merc will work with the older Airguide tachs. I'd really like to keep my tach as it matches the speedo and they are in good shape, plus just look great on a boat of this vintage.

How do I know which Mercs will work with the Airguide tach? Is there a module that can be made to convert tach signals for the older Merc's that do not already work with Airguides? Thanks for the help!

Phillip

Here is an airguide site that will have the information you need.

Greg Anderson
Wisconsin

www.classicboatwork.com/classicparts/gauges/airguide/airguideinstructions/Airguide_Instruct.html

great info provided there but there prices are astronomical. i've been lookin for one for my 700 for a year now. the one i got off ebay for 28 bucks is real nice but is for newer mercs. i'll switch it out when i find the correct one. ron