Tach reading ~500 rpms when not running (Quota)

[usedtobefast]

This is on a 2000 Quota 1100.  I've owned it from 20,000 miles to 21,500.
When I got it, tach was working fine.
Just noticed that now the tach indicates ~500 rpms when turned off.  When started, it is as if that 500 mark is now zero ... so at a real 3000 rpms it reads 3500 rpms.

A few things that happened just prior to this ... battery died (old age), put a new one in ... and the low beam bulb burned out, put a new one in ... neither of which I would think would mess with the tach's zero setting.

Bike runs great, all other electrics work great, tach needle movement is fine (no jumping or bouncing needle), just doesn't go back to zero.

No foreign item in the glass physically preventing the needle from going back down.

I did some searches and saw a bunch of dead tachs, or bouncing needles, etc. but nothing on this problem.

Is there some sort of "reset to zero" procedure? 

[rocker59]

How are you measuring the "real 3000 rpm"?

[Chuck in Indiana]

What Rocker sez.. it's just a number anyway. Working = good. 

[rocker59]

I've seen tachs do this, but they function normally while running.

Is the bike still showing idle speed of 1050 +/- when idling? 

Basically, if it's not working properly while running, showing the wrong RPM while running, best option is to source another tach.  You could crack open the case and see if you can find a reason for the malfunction, but you probably won't find anything. 

[usedtobefast]

I've seen tachs do this, but they function normally while running.

Is the bike still showing idle speed of 1050 +/- when idling? 

Basically, if it's not working properly while running, showing the wrong RPM while running, best option is to source another tach.  You could crack open the case and see if you can find a reason for the malfunction, but you probably won't find anything.

The tach indicated idle was ~1200 ... now it is ~1700-1800 indicated.  So the tach is showing ~500 rpms higher.

I thought maybe there was some magical reset procedure.   

[Xlratr]

Since it happened after you put the new battery on, have you tried disconnecting the battery?

[rocker59]

I thought maybe there was some magical reset procedure.   

Unfortunately, no.   

[Hymes Inc.]

Sounds like you've figured out perpetual motion.  Can't wait to see what you do with it.

[usedtobefast]

Since it happened after you put the new battery on, have you tried disconnecting the battery?

Yes.  Battery disconnected, it still reads 500 rpms, with motor off. 

Oh well, sounds like another quicky Quota thing.   

[rocker59]

Yes.  Battery disconnected, it still reads 500 rpms, with motor off. 

Oh well, sounds like another quicky Quota thing.   

Nah.  It's a Vaguelia thing.

[philwarner]

Yes.  Battery disconnected, it still reads 500 rpms, with motor off. 

Oh well, sounds like another quicky Quota thing.   

My 96 Cali tach stays at 500 RPM when shut off and sits at 500 RPM when I am sure it is idling higher than that.  I just finished balancing the carbs and set the idle a bit higher than it had been and the tach does not move off 500 until the revs are quite a bit higher by the sound of the engine.  The 500 when off concerned me when I bought the bike this year but I saw another similar year Cali on the net and its tach was also sitting at 500 with the bike off so I figured it was normal.

  I do question the accuracy of mine because when I am staying with traffic at 60 MPH (60 on a GPS) with the speedo reading 80 MPH, the tach is showing 2500 RPM.  Someone said I should be going 70 at 4000 if I have the 7/33 gearing and 80 at 4000 with 8/33 gearing.

[Kiwi_Roy]

Perhaps the counter weight has fallen off, it happened to my EV and I think its quite common.
Lots of the guzzi instruments have a stop pin that prevents the needle dropping all the way to zero.