a few quick questions

my bike is an 81 so the speedometer only goes to 80 and because of the laws back then it can't go much faster. what all would it take to make the bike live up to its full potential other than getting a different speedometer. would i have to re-jet it and if so is it a simple enough procedure?

 

The top speed of your bike is 120 mph, change out your speedo, like Bigfitz did, or get someone to follow you while you rip it up to check the speed & be careful.

 

is there anywhere i could easily get a speedometer that goes all the way up, does chacal have em?

 

Send him a PM, he might have a S/H cluster.

 

Yamaha mechanical speedometers (and tachs) are basically the same across about a 10-year period. Thankfully the 85mph madness only lasted about 4 years of that.

There are slight differences in the shape/depth of the frames, and the angle of the input bearing housing (what the cable attaches to.) The differences are not so great as to be insurmountable however.

There seem to be three basic "styles" of speedo: The "canned" ones; "early" with a staked-in trip odo and rotating reset knob, and "late" with a bolt on trip odo/reset mech. The slight differences in the way the frame is constructed can be compensated for with a little Dremel work on the case. There are also a couple different styles/colors of needles depending on the age as well.

The best place to find a different speedometer is eBay; what you need to find is a "canned" unit from probably an earlier bike, like about a '79XS. Those guts should pretty much drop right in.

Or you could bolt up a complete set from a later Maxim, and convert your tach to electronic. I'm eventually going to convert my tach so it exactly matches my speedo and get the cable out of the way so I can install an oil cooler.

Gear ratios are all the same, you can use anything you find that you like.