I was wondering if anyone could give me information on installing a tachometer on my M25 diesel.The boat came with just the basic control panel with oil pressure and engine temperature but no tach.The alternator looks original which would be from 1984.Thanks for any help
Tachometer install on a Universal M25
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Although I did mine on a different engine, the installation is the same. You will need:
1. Tachometer. I recommend this one, it's a great deal:
http://cgi.ebay.com/3888-Datcon-Tac...274?pt=LH_DefaultDomain_0&hash=item1c1217aafa
2. AC tap out of the alternator which you may already have. If you don't, it costs about $20 for a reputable alternator shop to install one. This sends the signal to the tachometer.
3. A means of calibrating the tach after it's installed. I recommend this tool:
http://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html
Harbor Freight is having a 20% off sale until Tuesday.
1. Tachometer. I recommend this one, it's a great deal:
http://cgi.ebay.com/3888-Datcon-Tac...274?pt=LH_DefaultDomain_0&hash=item1c1217aafa
2. AC tap out of the alternator which you may already have. If you don't, it costs about $20 for a reputable alternator shop to install one. This sends the signal to the tachometer.
3. A means of calibrating the tach after it's installed. I recommend this tool:
http://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html
Harbor Freight is having a 20% off sale until Tuesday.
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Is there any way to tell if my alternator has AC tap already on it, and if it does is it as simple as connecting the tach to it? I don't want to buy a tach and find out it won't work on my engine.It would be great if it is as easy as connecting 1 wire from the tach to the alternator and walla it works.Any help in the wiring process and calibrating of the tach would be great.
It would help if you told us what kinda of alternator you have. If it's the OEM Motorola, then it "could" have a tach output, even though your panel didn't have a tachometer. All of our C34 M25 engines had that OEM alternator with tachometers in the cockpit panels.
If you look at the sketches in this link, you'll see where the tachometer connects to the alternator, so go have a look at your alternator wiring.
http://c34.org/bbs/index.php/topic,4548.0.html
As far as calibrating it, don't waste any $$. Your engine should run at 3,000 rpm in neutral. If you buy a Telefex tachometer, their website has instructions as to how to calibrate the tach with the adjustments on the back of the tachometer.
If you look at the sketches in this link, you'll see where the tachometer connects to the alternator, so go have a look at your alternator wiring.
http://c34.org/bbs/index.php/topic,4548.0.html
As far as calibrating it, don't waste any $$. Your engine should run at 3,000 rpm in neutral. If you buy a Telefex tachometer, their website has instructions as to how to calibrate the tach with the adjustments on the back of the tachometer.
Tiny Tac
I second the TinyTac suggestion : I installed one on my Yanmar and love it . Very accurate, installs in minutes , and act as an hour meter too !!!
I second the TinyTac suggestion : I installed one on my Yanmar and love it . Very accurate, installs in minutes , and act as an hour meter too !!!
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