Speed sensor?


Do speed sensors just go bad? I have a 2006. Haven't had my bike out much this summer -- had it out a few weeks ago and the speedometer was jumping all over the place.

Over the weekend I removed the front sprocket cover, cleaned everything and made sure the sensor wheel was tight. Sensor wasn't physically damaged. I also unplugged/replugged the sensor. Still jumping.

I don't mind buying a sensor, but I wanted to ask if that is somewhat common or if I should look at something else first.
How dirty was the sensor? They are easy to change see if you have a friend with a bird that will let you try his sensor
Wasn't very dirty -- kind of had a 'crap' moment when I saw that it was quite clean and that the wheel was tight. I don't have any friends with one. Looks like there are some 'tested' ones on ebay for around $29 -- not against just trying that for $29, but thought I'd ask.
check the back of the speedo, plug might be loose mine did the same thing
Unfortunately the ebay seller sent me the wrong sensor. I checked the plug in the speedo -- used a little contact cleaner and it's nice and tight (still doing it). If it's not the sensor I don't know what else it could be.
Bad news is In my service manual it says if speed sensor ok Replace Gauges . Not much between to go bad .
Ok. Thanks. Working on getting a sensor. Need to see what the ebay seller might do tomorrow -- otherwise I'm just going to order new. Thanks for the reply. Hopefully that's it.
Unfortunately different sensor is acting the same. Will take it to a shop. Not much left other than the gauges and the wiring harness. I did drop it in the driveway earlier in the summer -- can't imagine that would be enough to damage the harness.