My first street bike was a ysr50 lol. Bought somewhere around 5 years ago. Just sold it a year ago. I had the first year and it looked just like the picture you posted. I took it to the track once, but it was ALOT of work! And in the dead of summer. The most popular track in so cal is grange.
Grange Race Track Southern California race track for Kart and Supermoto Racing I know Buttonwillow also has a kart track too but I've only been on grange. This is the race group I thought about joining but decided I didn't need another hobby.
CMRRA I bought the bike for about $2k and sold it for $2k. I see them pop up for sale all the time. Mine was all original which is a bit rare and can be expensive.