SR20 G2 Tachometer Generator

Anyone has the part number and model number for the tachometer generator for SR20 please?

I can’t read the model number or part number, because it is written by hand and faded. It is made by “Rochester Gauges”.

Anyone knows if Is there are any suppliers other than Cirrus that sell these tachometers?



The part number of the tach sensor is 12323-001. I just had to replace mine. $695 for about a $20 part. With API out, Cirrus is the only source.

Thank you Warren for your reply.

Just as matter of interest, what you call a Tach sensor, is this the same as the Tacho Generator (Part Number: 12620-001)?

Also you wouldn’t have access to the details specified by the manufacturer of the parts, which on mine is hand written on a label and stuck on the side of the generator, well the name of the manufacturer is “Rochester Guages” ?

These Tacho generators are not specific to Cirrus, so if I could find the model number and manufacturer’s part number (not Cirrus’s part number), then I will be able to hunt around for any supplier of any aircraft, which uses the same part!! My last resort will be Cirrus, for the same reason that you have just stated, their price!!!

Many thanks


Mo—Replacing this tach generator/sensor and the problems I have had are too long to go into here. You can call me at the number below. I ordered the part from Twin Cities Aviation, 12323-001, which was drop shipped from API, and had my local A&P install it. It read about 250 rpm low, but I put up with it and used a little TrueTach for my rpm. Then later this summer in NH, had a service center try to figure out what was wrong. They pulled the tach and discovered the label on the wiring harness had part number 12323-001, but the tach body label showed it was a 12620-001, Rochester Gauges. So, they ordered another one from Cirrus, which I had to pay for again. New one works perfect.

API is no longer, and I haven’t heard back from Twin City Aviation, so I ended up paying for 2 of them. My penalty for trying to do this myself.

My suggestion is to have a service center deal with it, they will make it right. BTW, my original one had 12323-001 on the label, the body read 12620-001. I don’t understand their labeling system.

727 two three seven-1897.


Thank you very much for the information. As you said, if I was to buy the part from Cirrus, I need to use your part number (12323-001). Just managed to get a price from TC Aviation (Nearly $700) I have a Cirrus engineer coming to have a look at the unit/wiring this Friday. Hopefully he will be able to work out the source of the problem.

TC also told me that, there is a company called “Dallas Air”, which is an FAA authorized center and repair these devices professionally, I don’t think of repairing to be a good option, but on this occasion it can help us to eliminate the possibilities i.e. if the problem is the generator, the wiring or something else!! My real problem is to keep the aircraft flying because it is used for training. So we might be interested in buying a serviceable second hand one after Friday.

By the way our problem is this: when the aircraft is started from cold, the indication will stay on zero, after a few minutes it fluctuates between its real value and zero, and when in flight (cruise) it behaves normally, including after landing taxiing etc. When the engine is shut down and restarted, the problem also restarts itself !!

Thanks again


The tach gen on my SR20 started doing that this summer. But, within 2-3 flight hours it quickly progressed to the point where it read “00” all the time, and was replaced by a Cirrus SC ordering a replacement from Cirrus. The replacement worked for about 4 hours and then started reading several hundred rpm low. Cirrus replaced it at no cost, and on the last flight, after about 6 hours of run time, I realized it is reading 100-200 rpm low again. So, back to the shop.


Thanks for the information and sharing it with us.

I am not sure if your problem is the tacho generator. If it is, then Cirrus really need to kick some butts. It isn’t fair to get customers to do the trial and errors on manufacturers parts.

As soon as something doesn’t work, the Maintenance recommend to change the first item that they can get their hands on, if that doesn’t fix the problem, then move on to the next one, in between the trusting customer has to pay for the poor design and the trial and error procedure carried out by the so called engineer.

As it stands, I am not going to change anything unless I am absolutely certain that the component needs it and that if it doesn’t work, the item will have to be taken back. Unfortunately due to the nature of aviation industries and that most aircraft owners are perceived to be wealthy therefore won’t mind the charges as a whole, so taking the customers for a ride is never an issue and nor is morally wrong.

I had a bad experience with an overhauled MCU purchased by the maintenance company last year. 2 or 3 of the current sensors inside the MCU had to be replaced. Which actually took a number of visits and test flights to find the offending components as they were intermittent. I still get glitches from time to time with ALT-1 or ALT-2 light coming on.

I guess Cirrus will need to find a way to have a better control over the quality of parts they are buying in. There is just far too many electrical problems. At the same time, the only way that I can see might help to improve the reliability of the parts supplied, is complains raised by the inflicted customers.

Mo - UK


Many thanks for helping me out with your tacho sensors. Air Dallas received both units and were also very helpful in testing the units and made a working unit out of the 2. However, Rochester guages who are the manufacturer of the unit refused to supply the “Functional Test Procedure” so no testing for certification could be carried out. Rochester reason was that those details belong to Cirrus and if we need one, we should buy a replacement unit from Cirrus which as you know cost around $700. (By the way Cirrus denied the exclusive use and confirmed that the unit is also used in other aircrafts i.e. Seneca or bonanza).

I had one of the unit taken a part, and shockingly witness the poor quality and cheapness of the unit and the way it was put together. I am not surprised the unit fails after so many hours. In our aircraft it was replaced in late 2011 and the unit has lasted about 400 hours. The main component in the unit is a position sensor made by Honewell and retails around $15 (517SS16).

**I can also tell you I have seen bicycle speedo with better quality and reliability than this Tacho Sensor. **Once again, it proves the point that, some manufacturers perceive the aircraft owners to be nice and generous, whom are generally prepared to pay whatever price they ask for and easy to be taken for a ride.

I hope Cirrus are aware of the various problem with this Tacho Sensor not just the quality and price of the unit. The “percentage power” relies on the output from the Tacho generator, so any false feed results in an incorrect calculation of percentage power and the RPM indication, hence possibility of setting up the engine incorrectly.

I am also hoping Cirrus to consider putting time limit on this unit, so it is changed after so many hours, this is to protect the engine from getting abused in flight. An engine that costs over $40k deserves a more reliable instrumentation, than a 60s piece of s…t. design.

Replacing tachos 3 times in 10 years is much more than a coincident!!!

There is two different tach generators with the same part number. The original had a very thin shaft that wore out very quickly. The 2nd generation, per say, has a more robust shaft and lasts quite a bit longer. When ordering make sure that you ask for the latest version. I found out the hard way that there are quite a few of the originals still out there.

Many thanks for the information, hopefully the supplier (Cirrus) will be fair in supplying the latest part. I must say this though, this is not Cirrus’s fault as they are also trusting in manufacturer’s like Rochester.

The next challenge is to get the engineer back and get him to measure the prop revolution and compare it against the RPM indicator and will let you guys know.

I don’t agree. This part has been problematic on the SR20 since the beginning of the product line. There are other ways to measure RPM’s that could be employed (some have been upgraded in the field). Cirrus has not taken steps to improve their vendors reliability or your cost of operation and is something I think Cirrus could do. They could offer a SB for an improved design that owners could pay for and be better off in the long run.

Roger, thank you for your comment. I do agree with some of what you say.

I am not just sure as the type of approach Cirrus could take to find a replacement. The problem is the SR20 market is quite small so the development cost could become an issue, although selling a product that can cost no more than $30 to produce for $700 should be a good tempter and certainly help the cause.

All I can tell you is this, neither Rochester no Cirrus Could have got away with the current part, had it been manufactured in Europe!!!

I will be writing to Cirrus on this, as this particular part can become an indirect cause of a cylinder failure.