Good idea on the drill GTO. I took the cable out from the engine end and put it in a cordless drill. (FYI..be careful not to chuck it up too tightly or you'll "pinch" the gap in the end together). Apparently something in the gauge itself was bound up a bit, or sticky or something. I ran the drill a bit (in reverse to "increase rpms on the gauge) and it went up to 1200 or so. I then ran it "backwards" for a bit, then forward, back and forth for a while, and the max rpm's on the gauge gradually increased. Finally maxed out at 2400-2500 rpm (which I suspect is the max reverse rpm of my drill). Put it back together and seems to be good now! ;-) Now...I would like to get a comparison reading somehow. Any suggestions on pulling a comparison RPM reading? Harmonic? Optical? Electrical?