Changing instruments on a 1981 motorcycle?

Question

I have a 1981 yamaha xj550 seca and I'm looking to change the instruments to either after-market or a different model. I think the plastic and the shape is terribly designed. How do I figure out what is compatible with my model of motorcycle. Thanks.

Answer 1

First of all, you need to know whether your bike has mechanical or electrically operated instruments. For Kawasaki, '81 was the first year for the electrical jobs. Most mechanical instruments operate on the same drive gear ratio and use the same size cable end, so changing that shouldn't be that big of a deal. Electric tachs are common and most operate off of a signal obtained from the ignition coil and can be used even if the orginal was cable driven. If the orginal speedo was electrical, you'll need to find a replacement that's compatible because they're driven by electrical pulses sent from the sending unit at the front wheel. You'll need to make sure the instrument and sender are compatable to obtain accurate readings. For example, my bike's sending unit produces 23 pulses per wheel revolution and the speedo is designed for that many. If yours is electrical and you wish to go mechanical, you may be able to find a mechanical drive unit from an older bike of the same manufacture that would interchange. That shouldn't be too hard since it was easier to design a new electric drive unit to fit existing fork legs and wheels than the other way around. Also see is there was an "economy" model that was similiar to your bike. The economy Kawasaki's used mechanical instruments while the others used electrical.