Well just as it says, I took my 98 superhawk out today, I washed it and I didnt notice if it was working at first, then I was crusing and noticed it was sitting the peg (0) and the milage wasnt working. I stopped and ate somewhere and when I got on it again it was working fine?

I did the search thing and it sounds like the speed sensor is pretty reliable. Is there anywhere I should check for corrotion?

 

it may be your regulator rectifier, they do that when they start to go out, its no longer letting enough voltage get through to run the gauges and after you park it the r/r cools then works again for a little while

 

Yea if your battery or voltage levels do anything strange soon, you will know.

 

You just got too much water on the back of the gauges when you washed it.
Mine used to do the exact same thing, just be careful when you spray the water and even if it does happen again, it's no big deal as it will turn on again after it drys out and you cycle the ignition switch,