Does it show hours by "pto speed"?
My B7610 does. I can work it for 10 hours well under "PTO" speed and it will only show a couple.
Hours are based on engine speed I do believe.
how long did you spin it with the drill??
I dont know how fast that turns with the engine running, But engine running at PRO RPM (prolly around 2500), it would take 6 minutes for it to even advance 1/10 on the meter.
I spun it in reverse for over 10 minutes and the drill spins at 3000 RPMs.
If its a mechanical meter it can be "adjusted". Back in the day there were guys who made a business of turning back speedometers for used car dealers. The mechanical parts inside are basically the same. Don't know the degree of difficulty not seeing the meter. Just take a look at the meter if it is assembled with screws then most likely it could be easily "adjusted" by disassembling and reassembling with the digits rearranged.
The dash had not been into so I doubt that happened.
I think this was all a case of me being paranoid.....typical