BMW recommends changing the spark plugs and the air filter every 20,000 km. But to me, they both look good after 20,000 km...the bike starts immediately, runs strong, runs smooth, lots of power, good fuel economy...so I am asking myself why spend $100+ if I don't really need to change them after 20,000 km??
Just wondering how often other people are changing their:
1. Spark plugs
2. Air filter
Thanks for any feedback.