Recommendations for laser tachs?

Geoff W.

Makes Up For It With Enthusiasm
Blogs Author
As the title says - anyone have recs for a remote tachometer I can use to verify my tach readings? Looking on Amazon they seem to range from $20-200 and I'm not sure what I'm looking at, to be honest.
 

Alan Gomes

Sustaining Member
I use this one. Of course, I haven't checked this tach against a known standard. However, I checked it against a friend's optical tach and they agreed. Plus, the numbers it gives me seem believable, FWIW.

My Yanmar tach, by the way, is off, though not in a linear way. It is more accurate at the very low and high end, drifting off by as much as 250 rpm at worst. I made up a deviation table for it. But really, since I try to run the engine within a certain range of cruising rpms, those are the only numbers that interest me.
 

Roger Janeway

Member II
I have had very good experiences with the Neiko 20713A Digital Tachometer. I tested it on various things off the boat with a known RPM and it was accurate. It is very easy to use, and reports a minimum, maximum, and mean for the period of time that you point it at the rotating shiny thing and hold the button. My experienced local diesel mechanic was initially suspicious of the ~$20 Neiko until I used it to demonstrate that the tachometer his technician had been using to test my driveshaft RPMs was inaccurate.

 

1911tex

Member III
I just borrowed this one from a neighboring boat at the marina. He showed me how it works...put a piece of shiny tape (included) on the flywheel (crank BELT pulley) and point the instrument at it once engine is running. He compared it to his Catalina boats' RPM gauge....which was off by 155 rpm at idle, 240rpm at 2000 rpm and 310 rpm at 3000 rpm. I have a different one on order (wish I had known he had one); however, these instruments work!

 
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Geoff W.

Makes Up For It With Enthusiasm
Blogs Author
My main takeaway is the $20 variety should do just fine. That's a relief! Thanks everyone for the input. It's funny how being a sailor has now made me suspicious of NOT spending a lot of money on a doodad or piece of equipment.
 

mbp

Ericson 34
And I have this one.
There are perhaps a dozen versions of this tachometer that are almost identical. They look like they are made by a single manufacturer and then relabeled.

I bought mine for a previous boat that did not have a tachometer so I could have some idea of engine RPM.
 

ignacio

Member III
Blogs Author
I replaced the tach on my Yanmar 3GM30F a few weeks ago. The old OEM tach used a magnetic sender on the transmission bell housing. The new tach runs off the Balmar alternator I installed a few years ago. Not having a digital tachometer handy once I had everything installed, I was curious to see if there’s any apps that could help me at least get in the ballpark with calibration of the tach. To my surprise, there’s a few apps - some work using the phone’s light and camera, others use the microphone and an algorithm to analyze the engine sound patterns at idle. Out of curiosity, I tried the latter. It came in at 860 rpms, in the range specified by the manual. So I set the tach to that. Then increased to 2500 rpms. The app detected the change and matched to within 5-10 rpms. I’ll probably still get something more accurate later, but it’s good enough for now to get me out sailing.
 

Alan Gomes

Sustaining Member
I replaced the tach on my Yanmar 3GM30F a few weeks ago. The old OEM tach used a magnetic sender on the transmission bell housing. The new tach runs off the Balmar alternator I installed a few years ago. Not having a digital tachometer handy once I had everything installed, I was curious to see if there’s any apps that could help me at least get in the ballpark with calibration of the tach. To my surprise, there’s a few apps - some work using the phone’s light and camera, others use the microphone and an algorithm to analyze the engine sound patterns at idle. Out of curiosity, I tried the latter. It came in at 860 rpms, in the range specified by the manual. So I set the tach to that. Then increased to 2500 rpms. The app detected the change and matched to within 5-10 rpms. I’ll probably still get something more accurate later, but it’s good enough for now to get me out sailing.
Can you provide the name of the app? IPhone or Android? It sounds interesting.
 

Bolo

Member III
I have had very good experiences with the Neiko 20713A Digital Tachometer. I tested it on various things off the boat with a known RPM and it was accurate. It is very easy to use, and reports a minimum, maximum, and mean for the period of time that you point it at the rotating shiny thing and hold the button. My experienced local diesel mechanic was initially suspicious of the ~$20 Neiko until I used it to demonstrate that the tachometer his technician had been using to test my driveshaft RPMs was inaccurate.

At $22 and over 350 reviews with 4.5 stars on Amazon the Neiko 20713A Digital Tachometer seems like a good purchase. I’ve also been looking for an inexpensive hand held tach for my boat.
 
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