I noticed my tripometer isn't working anymore. I filled up Friday and cleared it. Later I looked, it was 2.8 miles from home to the gas station. Saturday I rode for 86KM. Sunday I washed the bugs off and did some polishing. The trip was not working anymore. BUT the odometer IS. How do you explain that with these bikes? How do I fix it?

2001 CBR 929 RR American model living in Portugal.

Steve