I didnt own a bike in 1990, but was was lucky to be let to sprint race an 86 RS250 Honda 1x, and sprint race a 1990 TZ250 1x. I have been doing research this week, and apparently those type of bikes (2-stroke race bikes) need the top-end rebuilt every 200+/- miles and crank rebuild every 600-mi +/-. And even crank replacements/rewelds quite frequently. This seems like a lot of money in hard to find parts, if true. The 2-stroke streetbikes of that era (RZ350/Gamma/NSR/etc) not need this type of investment/maintenance to ride. Why cant you TD or race a season on the motors, why u have to rebuild constantly???? I dont understand. Thank you.