I'm 5-sec off 250-record (street-based 4T) at Thunderhill, and don't think focusing too much more time on that in next 3-yrs is most effective for my training. When I renewed my season-pass in January, they suggested I do A-group since B is always full. But Ninjette will put me at bottom of A. I'm getting itch to beat up on litre-bikes in A-group this year. So RS250R with 100-lbs less weight (220-lbs) and triple power of my Ninjette will let me do that with shaving off 10-15sec/lap!
It also costs less than track-prepped litre-bike, although I'm planning on spending 2-3x that on maintenance and rebuilds. With modern coatings and metallurgy, I hope to extend durability significantly over what was available in '90s. One of my clients who builds artificial hearts with mag-lev motors uses an off-the-shelf diamond-like coating that's +5x more durable than Nikasil. That's very promising for bearing-surfaces and cylinder walls.
Maintenance-schedule for RS250R looks like this from service-manual:
