The purpose of this post is to acquaint you with exactly what's inside the typical Yamaha mechanical speedometer and tachometer. I am NOT advocating tearing your instruments this far apart. The speedo that got completely disassembled was in pretty sorry shape, it came from a "canned" unit off a '79 XS. The bike had been down at some point, the back of the speedo frame was tweaked and the input bearing was pointing a few degrees off center. I chucked it in my vise and whopped it with a non-marring hammer and it straightened out pretty well. Anyway, here's what's INSIDE your cans or clusters: Typical Yamaha mechanical Speedometer and Tachometer How they work: Cable attached at "A" turns input shaft, which has magnetic head "B." The spinning magnet "carries" the needle shaft cup along for a ride, winding the needle return spring "D" as it moves the needle "E." Tach and Speedo work the same, except the Speedometer has ODOMETERS added, the trip odometer is already off both speedos used in this case, it makes it easier to see the other "guts:' Input head "A" turns worm gear "B" that drives shaft through gear "C" and turns odometer "D." Gear "E" drives the trip odo which is removed on this one. (It attaches at the blue arrow) So let's take one APART! On most of the newer units that you'll find in the XJs and FJs parts "A" and "B" are swedged in place and can't be removed. I took this one apart so we could see what's inside where you normally can't see. It helps with the lubrication if you know what you're doing "blind." Needle "C" is pressed on a knurl on all of them that I've taken apart. I try to avoid removing the needle whenever possible. The critical part you REALLY can't see: The needle shaft "cup" rides on a pointed spindle in the bell of the cup; it's supported by a bushing and the support "bridge" will be swedged in place on most newer instruments. The other part you normally can't see: The support bearing for the cup spindle. See how gummy it is? The needle shaft knurl: If you DO pull the needle, I recommend a 3-molecule microdroplet of adhesive on reassembly. WHAT YOU CAN DO: CLEAN and lubricate. For cleaning, mineral spirits or paint thinner and q-tips; lots of q-tips. MY PREFERRED LUBRICANTS for instruments: Lube the INPUT BEARING here: (Remember, tach and speedo the same) And here: Lube goes between the inner and outer parts. The hole is just for the cable and is blind. TRYING to lube the blasted spindle and support bearing is the challenge; you have to feel for the spot with the tip of the straw. Tach: Speedo: SPARINGLY lube the needle shaft bushing; jam a q-tip in there to sop up any excess: Tach: Speedo: Cleaning and LUBRICATING both tach and speedo can resurrect a failing or sluggish instrument. LUBRICATE SPARINGLY. THINK IN TERMS OF DROPS Put a DAB of silicone grease (JUST a dab) on the various gears, reassemble and test. Hopefully, knowing what's inside there will help you save a speedo or tach.