engine tach bouncing-gctid345996

[Guest]

I have EH 700 TIs and my starboard engine tacks are bouncing both in the pilothouse and the flybridge. Is it a sending unit or something like that? I hope that I can replace it myself because I am in FT Lauderdale and they are crazy down here cost wise.

Thanks

Kenni

[Foster]

Since both tachs are bouncing, it's something that's common to both gauges. That would be the sender unit and possibly the wiring to the pilot house (my wiring goes to the pilot house first then to the upper helm station) I'd look at the connector on the sensor then the connections at the pilot house.

The sensor pictures I looked at appear to be held on with a single bolt, you can always try to swap the sender units to see if the problem moves. If it does then it's the sender.

[Guest]

what pictures

thanks

kenni

[Foster]

I used my Google skills (Hino EH700 tachometer) clicked on the image tag and looked.

I got this site:

http://www.boats.net/parts/search/Merc2/Mercruiser/EH700 (175-220HP) HINO 393 I-L6/ALL/ELECTRIAL COMPONENTS/parts.html

Part #7 is identified as the tachometer sender.

Looks pretty simple, unplug the connector and unscrew it from the housing.

[LTCret]

When I had that problem it was in the multi-wire connector between the engine wiring harness and the boat wiring. In my 38 the connector is located on the port side of the engine. My manual explained how to take those connectors apart and clean the wires.

End of problem for me.

Good Luck