Veglia tack off

[fotoguzzi]

Brand new white faced veglia tach reads 4000 rpm at idle, any ideas if there’s a fix?

[bad Chad]

There’s a fix, but it’s got to be north of $200 by now. 

Paspeedo.com

[cliffrod]

Brand new?  Any chance it’s a cheap repro and not a real Veglia?

[fotoguzzi]

Brand new?  Any chance it’s a cheap repro and not a real Veglia?

it came from a closed dealer stocks, not a single mark or scratch on it.

[80CX100]

it came from a closed dealer stocks, not a single mark or scratch on it.

     Check for any part #'s that might give you a clue what bike it was meant for.

     You might want to search for it,but iirc KiwiRoy did a thread back in the day on getting the right signal set up when adapting an electronic tach from another bike and getting 2X or 4X the actual reading.

     It had something to do with differences on how the sensor took it's readings with sensors in different places,ie flywheel,crank etc.

     fwiw

[Moparnut72]

     Check for any part #'s that might give you a clue what bike it was meant for.

     You might want to search for it,but iirc KiwiRoy did a thread back in the day on getting the right signal set up when adapting an electronic tach from another bike and getting 2X or 4X the actual reading.

     It had something to do with differences on how the sensor took it's readings with sensors in different places,ie flywheel,crank etc.

     fwiw

Exactly, crank, cam, wasted spark etc.
kk

[nsmith]

I'm the guy with the out of range tach. the tach in question is a part number 037672000
the Part number for a white faced tach at Harpers moto guzzi is 027672000
I can't read any numbers from the original tach. Seems like one was made for the small icm and the other for the large icm, if that's the right word.
But I have no way of confirming that. I have sent an email to Harpers so with any luck I can get an answer soon enough.

[nsmith]

I just Went back to Harps Websight, entered an older model Guzzi with the big board and that bike uses a different part number that the one shown for the small board bike so I think I found why it reads way off. I will still wait to see if Harps responds to me email.
Thanks
 

[fotoguzzi]

That’s very interesting Neil . I’m out of town now but will check a few things when I get home.

[nsmith]

Harps answered my email stating the one I got the other day may have come from a Centauro. Either way there are diff. white face tachs for diff. models. Life a little, learn a little.

[fotoguzzi]

I'm the guy with the out of range tach. the tach in question is a part number 037672000
the Part number for a white faced tach at Harpers moto guzzi is 027672000
I can't read any numbers from the original tach. Seems like one was made for the small icm and the other for the large icm, if that's the right word.
But I have no way of confirming that. I have sent an email to Harpers so with any luck I can get an answer soon enough.

the Harpers number 02767200 is the part number in my Bassa parts book. The smaller ECU. JUST FYI

[LowRyter]

If it rattles, the counter weight needs to be epoxied back on.  It's a real PIA to get the bezel off and back on.

If you don't want to attempt it on your own, contact Joel Levine repair shop.

[fotoguzzi]

I have a theory.. this tach in question is for a 98 EV and other bikes with the BIG ECU and it get the signal from the crank sensor. In the OP’s case it’s getting the signal from the cam sensor which runs twice as fast as the crankshaft. Although I’m a little skeptical that the two tachs are different at all? Wouldn’t the ECU of both give a rpm signal not a phase sensor signal? When I get it back I’ll try to find a 98 EV to test it on.
-edit, got that backwards.. crank runs twice the cam speed.

[PeteS]

I have a theory.. this tach in question is for a 98 EV and other bikes with the BIG ECU and it get the signal from the crank sensor. In the OP’s case it’s getting the signal from the cam sensor which runs twice as fast as the crankshaft. Although I’m a little skeptical that the two tachs are different at all? Wouldn’t the ECU of both give a rpm signal not a phase sensor signal? When I get it back I’ll try to find a 98 EV to test it on.

Tachs are in fact different. They can be interchanged if you hook them up to right place. If this is reading high then wire it to one of coil primaries as it should only fire every other rev instead of every rev. If it then reads 2000 RPM and you think it should read about 1000-1200 well they aren’t called vague liars for nothing.

Pete