• Wishlists
  • 877-477-7823
  • Contact Us


Add to Wishlist
Part# 10-25200
MFR Model# R-1


These Digital/Graphic Instruments are solid state and hold their accuracy over time and a range of environmental conditions. The colorful Graphic Analog display emits green, yellow, or red light enabling the pilot to spot problems immediately without interpreting a needle. The Digital display constantly provides an exact indication of each instrument function. Gauges mount in 2-1/4" instrument holes. These instruments (except fuel level) are STCd & TSOd for certificated aircraft.

R-1 Tachometer

The R-1 is a precision RPM instrument featuring a 210 degree graphic analog display and a full four-digit digital display. The 10 RPM resolution allows for precise RPM settings. The R-1 features a tach time recorder which records the time the engine is operated over 1300 RPM as well as an automatic flight timer which records the time starting when RPM reaches 2000 (takeoff) and then drops below 2000 (landings). Installation of the R-1 is simple. It connects to the mag. lead through isolator and requires no cables. It is backlit and operates on 12-24volt systems. Wt. 10 oz. Max. Digital Range 5000 RPM. Accuracy 1%. Specify red line, yellow & green arcs, and magneto models, as well as aircraft make & model.

E.I. products include all documentation and certifications

R-1 Configuration Worksheet (Required for Order)

FAA Approval

  • STC'd, TSO'd, PMA'd
  • Customers Also Viewed
  • Frequently Purchased With
  • Related Items


Iâve bought these twice and love them. Many people donât realize that old faces in old airplanes are usually about 200 rpms off, they die a slow death. This is highly accurate and was about a 90 minute DIY project with supervision.

Av- F
June 23, 2018

Drop shipment arrived earlier than expected.. Thanks to aircraft spruce and electronics international

Sansone S
June 6, 2018

Easy to see and operate. The mag drop feature works well. Takes some getting used to looking at a number instead of a needle. The lights help though. Installation took the avionics tech about three hours. No surprises at all. My only complaint is that the instrument doesn't come in 3-1/8 size. The included adapter plate worked well though.

Edward S
August 15, 2015

This review does not reflect Aircraft Spruce, but EI. The QA and customer service at EI is awful. I specifically ordered a 6 cylinder variant through Aircraft Spruce. EI confirmed that all the data was transmitted and correctly entered on the invoice. However, when I received the unit, it read 50% high. EI determined they mistakenly calibrated it for a 4 cylinder and had me to send it back (on my own dime). What was quoted as a 1 business day turn around turned into a 4 business day turn around. And then they shipped it back via ground instead of air, despite ASKING ME MY PREFERENCE AND THEN TAKING MY CREDIT CARD NUMBER TO PAY THE DIFFERENCE. I will absolutely never buy another EI product in my life. If these type of lapses in QA are the norm, I can only imagine how thats reflected in the quality of their products. And my airplane sits for another week due to their carelessness.

Seth H
November 22, 2019

Mine is about 3 or 4 years old and has become sensitive to humidity as it reads a very high number - even when the engine isnt running. I called customer support and they said that it can be resealed for $125. EI equipment is only warrantied for 1 year. I would think that my problem is based on defective materials, workmanship or design. The factory new unit didnt last long and there was no mention as to how long resealing would last. Theyve been making these units for quite a few years and this is a known problem.

Kenneth P
January 16, 2019


Q: Does this only come in 2-1/4" gauge?

Yes, the R-1 only comes in a 2-1/4" gauge.

Q: What is the EI RC1 RPM TACHOMETER CAP 10-01223 listed accessory?

The EI RC1 Cap is used to cap off an existing oil pressured mechanical tachometer cap drive line so oil isnt spilled when replacing the new electric tachometer.

Q: I have a Pitts S-2B. I want to replace both front and rear Tachs. Can I run two tachs off the single drive?

Per EI, since this an electronic tachometer, this does not use a drive cable. This picks up the pulses from the magnetos which you tell you your RPM information. You can easily connect 2 of these electronic tachometers at the same time.

Q: Is this tach able to be used in a certified aircraft? Does this come with an STC?

Yes, The STC list can be found under the documents tab for the EI R-1 (10-25200)

Q: What information is required to order this instrument? I'm guessing red line and yellow arcs. Do you need current tach time of the tach that will be replaced?

Specify red line, yellow & green arcs, magneto models, engine model, and aircraft model. Current tach time can also be preset to reflect current time.

Q: Does the EI R-1 RPM Tachometer connect to both mags? How do you check your mag drop?

Yes, please see page 4 of the manual posted under the documents tab for mag drop procedure.

Q: Will a 1 amp circuit breaker be sufficient for this EI R-1 RPM tachometer?

Yes, 1 amp circuit breaker is recommended.

Q: Does this unit come with a 3-1/8 adapter plate?

Yes, an adapter plate for a 3-1/8" hole is included with this unit.

Q: Is the Electronics International R-1 tachometer approved for primary installation or backup only?

The E-1 is TSO approved and can replace your current primary tach.

Q: Can this EI R-1 RPM tachometer be hooked up to the Electroair electronic ignition? I do not see anything in the installation manual.

When you place the order for the R1 you will be asked for the type of ignition system. Per EI: the -LM version of the r1 will support the Electroair electronic ignition.

View in Catalog

View Image View in Catalog