Tiny-Tach Model TT2A

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Part# 10-04182
MFR Model# TT-2A


  • RPM reading adjustable from 1 spark per 2 revolutions to 8 sparks per revolution. One TINY-TACH™ now works for most gas engines.
  • RPM display from 1 to 19,000.
  • RPM update time 1/2 second.
  • Hour meter records total actual running time on your engine.
  • Job timer can be reset to record run time for record keeping.
  • Coax cable transmits signal without EMF interference.
  • 1 Antenna cable winds around your spark plug wire to give you the RPM reading – clean and simple to attach. Signal strength can be controlled by the antenna wire.
  • Standard cable length is 6 feet. If additional length is required, contact sales for special order.
  • TINY-TACH™ unit is potted to prevent damage from moisture and vibration. Lithium battery life 5+ years, not replaceable.

NOTE: Some engines, such as multi-cylinder outboards generate considerable electronic "noise" and may require a light filter to assure a clear RPM reading. You will find a "comments" section at the end of the order page where you can tell us about your engine – what kind and how many cylinders it has – so that we can make any necessary adjustments.

One year warranty

Note: This will not work with a shielded ignition harness or lead.
California Prop 65 Warning Symbol

WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov.



Richard C Verified Purchase


April 13, 2022

Worked very well- fast shipping. Wound highly recommend to others Thanks R. B.

Richard B
June 2, 2020

Great product

Darryl K
May 11, 2020

Replacement for my old Tiny Tach. Battery finally gave out. 5 yrs old.

Steve J
September 28, 2019

The battery in my first Tiny Tach lasted from 1998 until 2015. Results may vary.

Alex W
November 5, 2016

My Tiny Tach on my Starflight Ultralight with a Rotax 377 just died due to battery failure. It has been on the craft for about 20 years and until today was working great. I am disappointed that the battery is not replaceable (anyone know a hack?) but otherwise have been very happy with it and will replace it with the same.

Bob F
April 4, 2019

My tach has been in service for 4 years now and its still working well. I have a Lyc TIO540AF1B. We did have to cut a small opening in the shielding and then wound 10 turns over that opening (instructions recommended 3). It hasnt missed a beat since. Beats an optical tach as they dont work at night.

Carl B
May 18, 2018

If you are building an experimental and would like to use this device, DO NOT buy it until the last days of your build. The battery only lasts 5 years and is NOT replaceable. After that, its a Tiny Boat anchor.

Michael D
October 6, 2016

Battery died 2 weeks after install, no shorts in wires. Started acting up and changing rpm and an hour later stopped working. Not even a time used shows, junk. I bet they dont sell enough and are too old.

Donald A
March 30, 2021

tiny tachs do not work

Tony M
August 27, 2018


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: What model of Tiny Tach would work on a Lycoming 235 with magnetos and read accurately?

Part number 10-04182 is a universal unit and can be programmed for your Lycoming engine.

Q: Does this Tiny Tach Model TT2A come with a TSO approval?

No, this unit is not FAA TSO approved

Q: I understand the 10-4182 will work on the Lycoming engines.. will it count off the P-lead connection with proper resistive de-coupling? We don't wish to cut the shield on new plug wires. Is this your best choice for 1- self powered 2- Total tine counting 3- Tach Thank you frank

The manufacturer does not recommend connecting to the P-lead. You must cut back the shield on the plug wires in order for this device to work properly.

Q: Will the Tiny-Tach TT2A work on a Rotax 503 motor?

Yes, it will.

Q: Is the one you sale looks just like this one?

Yes, the photo is representative of the unit for sale.

Q: Is it possible to extend the wire, if yes, what will be the procedure?

This comes standard with a 6 ft lead. Longer leads are available but they are special order. Please contact our sales department for pricing and lead time of a custom length lead on the TT2A.

Q: What is the Tiny Tach TT2A setting for the 503 spark per revolution?

You will want to set the Tiny Tach to 2 sparks per revolution.

Q: How many wires to run it? The last tach for a Rotax 912 was 3-wire. Somehow it broke it before it ever would work.

This has two wires. One goes around a spark plug wire and the other grounds to the engine.

Q: Can add to the sender wire with a splice?

No, however you can special order the tiny tach with a custom length cable. Please contact our sales team for custom quote.

Q: Will this work on a Rotax 532 engine?

It should as long as the ignition harness isn't shielded.

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