The sender is a pulse generator just like a trigger in a distributor. The faster it turns the more pulses it makes. The changing into numbers is done in the speedo head and there is also a voltage reducer in the head that sends 6 volts to the sender, so you would think the 2 parts would be in sync voltage wise. But like you say, it could be a system voltage problem that the 6 volts is just half of the 12VDC and if it isn't 12 volts (it usually isn't as a charging system needs to be at 14 to 15 volts to charge the battery properly). They may have a supplier problem with the speedo head not meeting spec. If they are working with you it probably means they recongize there is a problem and will fix it. Where you going to be gone till next spring?

 

I spend as much time in Wyoming at our "ranchette" (too small to be a real WY ranch) as I can. Lots of great people, quad riding and fly fishing - just like your neck of the woods. I am hour away from a loaf of bread and love it that way. The rest of the year I spend w/the family in our home in Coronado, CA (San Diego). It's about a 1/4 mile from the Del Coronado Hotel of which you may have heard. I went back a couple of times this summer to see our son get his Eagle Scout and Black Belt. Yeah, I'm proud.

After selling my 300 I wasn't going to buy another machine right away but dealer has treated me very fairly in addition to bending over backwards when he didn't have to. He's selling his dealership due to his wife's health and I wanted to give him some business and ensure he got the profit, not the new owner. Hence, the new 650.

Where is the speed sensor located? Assuming it is accessable, would it be at all possible to machine a new impulse driver? Probably not worth the effort, but I'm thinking out loud here.

 

The sensor trigger wheel is inside the transmission and even if you did make a new one, you would only have the choice of adding or subtraction a tooth and that would be a major change in pulses. If you have 4 pulse per revolution and add a tooth to 5 pulse thats a 20% increase and if you subtract a tooth to 3 pulses that a 25% reduction. I still think the trouble is in the gear ratio change and the speedo head not being recalibrated to compensate for it.