Aviasport tacho. Hour meter not working?

[danny_galaga]

I have this tacho in my plane. Rotax 912 specific.

 

http://www.aviasport.com/Pagina_348.aspx

 

I must have run it close to an hour by now on the ground. The hour meter is supposed to measure time when the engine is over 1800 rpm. Because I haven't fine tuned the throttle assemblies yet most of the time it's never below 1800 rpm. But it seems to have stopped at 00:22. (I just realised that's in minutes, not 1/10 hours) .  The tacho seems to read rpm reliably.

 

Anyone have one of these tachos? Am I having a brain fart and not doing something correctly? I didn't think there was anything to do 🤔

[Blueadventures]

8 hours ago, danny_galaga said:

I have this tacho in my plane. Rotax 912 specific.

 

http://www.aviasport.com/Pagina_348.aspx

 

I must have run it close to an hour by now on the ground. The hour meter is supposed to measure time when the engine is over 1800 rpm. Because I haven't fine tuned the throttle assemblies yet most of the time it's never below 1800 rpm. But it seems to have stopped at 00:22. (I just realised that's in minutes, not 1/10 hours) .  The tacho seems to read rpm reliably.

 

Anyone have one of these tachos? Am I having a brain fart and not doing something correctly? I didn't think there was anything to do 🤔

I would email the company.  From what you say your getting pulse from engine with rpm showing.  I would also verify 12 volts to the + post. I had an issue with a gauge and most helpful with trouble shooting and then a replacement arranged with floods.  Roberto was the owner at the time 7 years ago.  110% product backup.

[skippydiesel]

As always, with 12V systems - Check your (-) earth/ground connections are clean & secure/firm

[sfGnome]

Look on the bright side. You’ll never have to bother with your 100 hourly inspections… 😛

[facthunter]

Unfortunately it doesn't work that way. You could use fuel used, but check on that. Faking required records doesn't go down well.  Nev

[danny_galaga]

5 hours ago, facthunter said:

Unfortunately it doesn't work that way. You could use fuel used, but check on that. Faking required records doesn't go down well.  Nev

I SUSPECT sfGnome was joking...

[danny_galaga]

8 hours ago, skippydiesel said:

As always, with 12V systems - Check your (-) earth/ground connections are clean & secure/firm

Tacho is working, so earth is fine. I have a feeling there is some sort of fault internally, but thought I'd check here in case someone knew something I didn't about it's operation. I will contact the manufacturer, hopefully they come to the party. That's a problem with builds isn't it? By the time you get to test stuff, most of the stuff is out of warranty 😄

[facthunter]

I do too.  but everybody reads this stuff.

Aren't they called a Hobbs meter?. I suspect that they are abit like some mechanical speedos with some skinny little gears involved.?  Nev

[danny_galaga]

59 minutes ago, facthunter said:

I do too.  but everybody reads this stuff.

Aren't they called a Hobbs meter?. I suspect that they are abit like some mechanical speedos with some skinny little gears involved.?  Nev

No, this one is digital. The tacho has an analog face (but no doubt converting a digital signal, same as my altimeter) and a little LCD readout at the bottom. When the engine is running it just shows the RPM in digital form as well as the analog face. But if the engine isn't running, it shows as an hour meter. 

 

If I'm stuck with this tacho (as in can't get it replaced under warranty) I will get a little standalone Hobbs or BDO hour meter. 

Edited February 11 by danny_galaga

[danny_galaga]

VDO

[cscotthendry]

Just had a look at the doc you posted the link to.

It says that when the engine is running over 1800 RPM, the readout shows RPM. It shows the time in Hrs minutes and seconds when less than 1800 RPM.

What does the display look like when the unit is powered but the engine isn't running? 
From the picture, it looked like the display only has 4 digits. I don't see how that can display H, M, S unless it scrolls somehow.

Also there has been an issue with Avia Sport tachos on Rotax engines. There is a thread about it on these forums.

I had an issue with erratic readings which I solved with a resistor between the signal and ground pins at the gauge connections.

[skippydiesel]

On 11/02/2024 at 7:19 PM, danny_galaga said:

Tacho is working, so earth is fine. ..................................

This could be faulty logic.

 

Partial/intermittent earth return, can effects 12 V systems in a wide variety of ways. Sometimes one system will show normal function, while another is completely dead.

The clever electronically savvy, folk on this Forum, will I have no doubt have an explanation.

 

[danny_galaga]

12 hours ago, skippydiesel said:

This could be faulty logic.

 

Partial/intermittent earth return, can effects 12 V systems in a wide variety of ways. Sometimes one system will show normal function, while another is completely dead.

The clever electronically savvy, folk on this Forum, will I have no doubt have an explanation.

 

The hour meter is built in to the tacho. The tacho is working fine, thus the earth is fine. Perfectly logical 🙂

 

On top of that, when the revs are above 1800, the hour meter switches to revs. It does this faultlessly.

 

I have a reply from aviasport. I'll see where we go from there, but I just bought an $8 hour meter from eBay as recommended by a friend. He fits them to all motorbikes he's owned. The oldest hour meter is 6 years now and still fine.

[facthunter]

Even Ride on lawnmowers have them these days. Nev

[danny_galaga]

Best $7 I ever spent 😊

[danny_galaga]

Inside the plane, on the firewall.

 

Rotate your screen 90° anti - clockwise for correct view 🤪