V7 Sport v T3/Lemans Tacho Question

[1down5up]

All - A question for the train spotters out there.

I am looking to put a set of v7 sport instruments on a Lemans project I am working on (bike was a basket case MK2, putting it back together as a 750s/v7 sport style)

The Veglia Tacho (black face) on a v7 sport Red Lines at ~7,000rpm and finishes out at ~8,000rpm

However on the Veglia T3/Lemans (Blue Face) the Tacho Redlines at ~8,000rpm and finishes at ~10,00rpm (in roughly the same arc/spot that it his 8,000rpm on the V7 Sport )

My Question for those that have made it this far, does anyone know if its just a difference in the internal gearing of the Tacho, or is it a different Pinion/Drive gear at the tach drive.

The Part number for the drive gear (the one with the 2 steel washers in the timing cover) is the same acros the big blocks (14 76 92 00), so it would just be a different drive gear on the camshaft (unlikly?) or different gear in the tacho....

For whats its worth the speedo is the same (160mph/240kph)

[guzzista]

methinks it's just plug and play for you and in the end you will have the same "Vague-lia" tach reading , just different graphics. Red line begins at approx 7500 on V7S and at 8000 on LM. Never had a V7S or Loop tach apart, but wouldn't be surprised if internals were cheapened on the blue faced deTomaso era Veglias

[1down5up]

Yeah, thinking more on it he logical answer is its just a slightly different internal gear ratio between the two tachos.

[Antietam Classic Cycle]

Either tach works on either bike, so AFAIK there is no gearing difference in the tach or drive gears. Perhaps Guzzi was just being a little cautious with the V7 Sport redline, found it wasn't necessary and revised it for later models.

Loopframe Guzzi tachs are electronic.

[1down5up]

Cheers Charlie, i'm thinking it may even be as simple as a stiffer return stpring in the tacho pushing against the revs of the cable that allows a different redline/max rpm position relitive to the face