'00 750 aftermarket DP guages

[DownwtheQuickness]

Hey all, I bought a 00 750 with 16k miles currently that had some aftermarket DP gauges put on by owner #1 (I'm #3).
The speedo is inaccurate - usually showing a speed that is +5-10mph over actual, according to other riders' speedos and police warning boards on the side of the road. Is there an easy way to calibrate that?

ALSO... The tach doesn't always like to work, esp when cold. Usually after warming up for a few minutes, I can give it a solid flick with my finger and it will jump back into shape and work just fine, but otherwise would prefer to just sit at 0.

Here's a picture of my gauges, let me know if the embed doesn't work...




Whatever help would be greatly appreciated. I'm not super experienced/knowledgeable about motorcycle maintenance, so to be safe, you might need to dumb anything down you think I might not understand 

[ducpainter]

10% error is not unusual on a Duc speedo.

That tach is very much like the one on my 2K 996. It had a bad solder connection inside. It wasn't rocket science to disassemble the gauge and repair it.

[DownwtheQuickness]

Thanks, Duck. I'll check the solder next time I've got the tools available to fix it.

I can live with the minutely erroneous speedo if there's no quick fix or error on my part for getting it that way. Got followed by a  biker to my driveway after work today and was afraid I had "miscalculated" my speed haha