Tach problems

[N24YW]

I was wondering if anyone has had a mechanical tach problem. I have a mechanical one from vans 315 hours on it and it seems to be off by 200 hundred RPMs (slow) I am going to get a electronic hand tach to verify but it sure seems to be off. It worked fine. Today it is reading slow. I couldnt get above 2500 rpms but I was indication 180mph. It idles at 400 rpm instead of 600.

Jim Knight
RV-6

 

[Mel]

200 rpm deviation is not that unusual for mechanical tachs.

 

[Kyle Boatright]

My mechanical tach went wonky at about 450 hours. I replaced it with a new one (Same Van's unit) for $90 or so.

 

[glfrdug]

promblems

Jim,
I have a mechanical tach from Vans as well. This summer at about 148 hours it starts going nuts....needle pegs then drops way off, then pegs again and I flew several flights and hours by hearing...amazing how you kind of do that anyway.
I contacted Van's as I thought my cable might be bad...they told me it was likely the instrument and not the cable, so I ordered a new one.
Installed it and flew a test flight...worked perfect. Next morning out to the field for another flight only to find the crystal face cracked right across. It looks like **** now.
Then on a recent flight to Lousiville KY for the Ryder Cup...GO USA...I noticed that the tach showed 5 hours of flight time even though the trip only took 2 1/2 hrs on my 8 day clock and watch.
Return flight the same...so not sure what to do now other that look for an electronic tach even though I want the old look.
DOug

 

[az_gila]

This might...

....
Return flight the same...so not sure what to do now other that look for an electronic tach even though I want the old look.
DOug

...work for you Doug.

http://www.aircraftspruce.com/catalog/inpages/tso_tachometer.php

An electronic tach. that looks like a mechanical one - the old look...

 

[glfrdug]

new old look

Gil,
Thanks for the tip...I'll look into this one
Doug