Thread Tools Search this Thread
Old 17 September 2012, 05:33   #1
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,614
Yam Tacho - Merc Engine.

OK, here's the thing. I have successfully used an old Suzi Tacho on a Suz, A Yam and my current Merc Clamshell.

In a fit of trying to make the boat look a little less "Mad Max meets Waterworld" I got a Yam tacho with a Blue dial to match the rest of the instruments. It's one of the "two wire ones - Here's the weirdness:

- When I connected it direct to the alternator output / Earthed to the block at the engine with the old Merc Rectifier, it read OK.
- When I put it in the panel & connected it as above - Nothing. (I tested immediately with the old suz tacho, and the wire is sound)
- I have since fitted a Honda rectifier / regulator to stop battery toasting, and the same thing happens.
- During my last cruise, it randomly for about 2 seconds jumped up to what I assume revs were (4.5K @20-ish knots) & died again.

(and I have put the old Suz tach in an ice cream tub & had it working OK since)

So, do I need a capacator / coil/ big resistor in the line? I assume the tacho takes it's power direct from the alternator (signal) line rather than a dedicated +12, and I am wondering if the internal resistances in the tach are not matched to the engine's alternator. The fact it works OK at the engine would hint to me that there is a resistance / capacitance issue with the run to the console.

I keep reading about certain tachos needing resistors / capacitors across the signal - Gnd terminals with certain engines. Anyone know if the same applies to the Yam tacho connected to anything other than a Yam engine?
9D280 is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 20:31.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.