3GM30F tachometer not working

Engines, Drive trains, Propellers, Steering, Ground Tackle and other mechanical system
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sailmon
Posts: 237
Joined: Sun Feb 22, 2009 6:53 pm

3GM30F tachometer not working

Post by sailmon »

HER Diamond is a 1991 F38 with Yanmar 3GM30F. The tach recently stopped working. I recently had the trans out & confirmed that pick up is in place & properly adjusted. Rather than going to trouble & expense of replacing the original system piece by piece (pick up, wiring, display) i am interested in hearing about other solutions people have employed. I am also wondering if it is possible & what is involved in having tach display appear on my Raymarine eS78 MFD.
Thank you,
Bob
Sailmon (Captain Bob Allenick)
S/V Her Diamond
1991 Freedom 38
Cleveland, OH

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GeoffSchultz
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Re: 3GM30F tachometer not working

Post by GeoffSchultz »

Are you sure that it's the tach that isn't working, or is it the wiring in between? I have frequent issues with my wiring/connectors.

-- Geoff
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1997 Freedom 40/40
http://www.GeoffSchultz.org

BillSmith
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Location: San Mateo, CA

Re: 3GM30F tachometer not working

Post by BillSmith »

Had a new tach installed and it will sit dead, pegged on zero unless I rev the engine to near max throttle while in neutral. Once done, consistent readout.
Bill & Carole Smith
Freedom 35 Pedrick
SweeTART
Coyote Point
San Mateo, CA

Tom
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Joined: Sun Jan 18, 2009 7:43 am

Re: 3GM30F tachometer not working

Post by Tom »

Please take a look at the TinyTac as a replacement/supplement as it's very small, very accurate and easy to install I have used one (mounted on the pedestal) for many years on Our Freedom, 39 PHS. My original tach works well but hard to see without bending over.

Tom Foster

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sailmon
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Re: 3GM30F tachometer not working

Post by sailmon »

Thanks Tom. Looks very interesting. If I mount on pedestal, would also get the tach up out of the footwell & up where it is more easily seen. How does the tack acquire its data? Off alternator? Other??
Thanks,
Bob
Sailmon (Captain Bob Allenick)
S/V Her Diamond
1991 Freedom 38
Cleveland, OH

Tom
Posts: 23
Joined: Sun Jan 18, 2009 7:43 am

Re: 3GM30F tachometer not working

Post by Tom »

The TinyTac uses the pulse of fuel on any of the high pressure lines going to an injector. That is converted to an electric pulse and sent by wire to the display. Check the diameter of your injector line, Google TinyTac for phone number. You will be taking to the owner and let him know the approximate length of run you will need to reach the display. Installation is easy. BTW, the display is enclosed in epoxy so very weatherproof.
Tom

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