if i bought a used set of guages, would i be able to take apart the speedo and change the mileage on the odometer?
How different are the miles on the bike to the gauge? If the gauges are significantly less than the bikes mileage and you're reselling the bike you can just disclose Not actual mileage.... Selling a bike with a lower mileage speedo and representing it as having the lower miles is odometer fraud..( It happens everyday I'm sure..just pointing it out..).
Yes you can alter the mileage on the gauge-- pull the glass bezel off the white bucket of the speedo ( pry the back rolled lip up all the way around the gauge ) and then pull the gauge itself out of the white bucket...(tripmeter knob has to come off) .Take a small screwdriver and you can tweak the high end of the mileage one way or the other.
Then just carefully reassemble the gauge.
And if they're close, you can just spin it with a small electric motor for a couple days. My brother would do that after rebuilding a car to get the odometer to read the mileage on the engine.