TOPIC:

The speedo on my '81 KZ 750 LTD stopped working
How do I tell if it's the cable, gear box or someting else?

First, check to see that it is still attached on the back of the speedo. If it is, disconnect it from the wheel and look at the cable. It's probably broken there.

Pull the cable off at both ends, turn one end and see if it turns at other end. Remove cable and inspect. If ok there , stick one end in spedo and spin (may have to try both directions) Most likly it's gonna be the cable as it does spin at thousands of rpm's. Make sure you lube new cable and relube it yearly.

I don't know if I'm reading this right and my apologies if I'm not but the cable doesn't spin at thousands of RPM's. I believe it's geared way down. Neither is the tach. I've checked the cable by taking it off the tach and running the engine to make sure it's turning. Put the bike on the centerstand have someone lean on the back lifting the front wheel, take the cable off the instrument and make sure the cable is turning in the sheath. It is a good idea to lube the cable/sheath at least once a year.

Say the cable is intact, and you are still not getting spin. How often does the gear on the front wheel go bad, and how hard is it to replace?

Really don't think it's your front gear. 98% of time its cable. I would guess other 2% would be gauge itself. I bet it is cable related if it just stopped working. Before jumping around just check the cable. Take it off and pull out the cable. It will only come out of the bottom. Inspect. One end has a rod with a split in it. This goes to the front wheel. The other end is squared off. Put some grease on it (cable) and slide it back into the sheath. Attach it to the wheel then spin the wheel until the cable seats. Attach it to your gauge and see if it now works. Make sure it is tightened all the way. Bet it now works....

I don't know if I'm reading this right and my apologies if I'm not but the cable doesn't spin at thousands of RPM's. I believe it's geared way down. Neither is the tach. I've checked the cable by taking it off the tach and running the engine to make sure it's turning.

The "spinning at thousands of rpm's" was kind of a joke.

Sorry Bluemeanie I just thought some people would try using it as a souped up dremmel! Hey wait a minut......No that'd never work! I think I did see a 2 stroke blender once!

Update; The cable is snapped down at the bottom. The slotted part fell out. Well, that happened.

Thanks!!

Make sure you lube the new cable real good. I'm sure there are many thoughts on this. I use a moly based wheel bearing grease and apply it with a small brush as I feed it into the sheath. Works for me...