I'm not convinced the CR is all that bad. Keep in mind that all that is to follow is my opinion and I don't claim to be an expert. I am also not offended by people who say bad things about CRs because they help me buy mine cheap ;)
I have the 00, 01, and 02 CR250s....currently, right now, at the same time.
I'd say that the 02 is not lacking any hit. I'd also say that the 02 is stronger than both the 00 and 01 where it matters (to me) on the track....in the middle. Maybe the 01 revs out further, maybe the 00 has a little more bottom end, I don't know, they are all so close it is hard to say. I do know that the 02 is most likely to stand up in third gear when it hits the powerband, and if I carry just enough speed through a corner with it, it is the easiest to jump a short approach with. I am an average rider at best, probably not that good, and relatively fat, so I'd say that the so-called lack of bottom end power wouldn't be a problem for people that can actually ride. I ride the 00 and 01 more because they seem to have less hit.
The 00 runs identically (as far as I can tell) with the Keihin and Mikuni carbs, if they are jetted correctly....same with the 01. The Keihin doesn't fit into the 02 good enough for me to run it...I can switch intakes on the 00/01. The nice thing about the Mikuni is if you are off that day, you switch the nozzle and main and go. There is little adjustment for the middle on the Keihin and you have to use the needle. The nice thing about the keihin is the screw off top and easily adjustable idle. My Keihin spews as much oil out the back as my Mikuni does when it is off. Everyday is an exercise in jetting no matter which carb/bike I am running IF I want it perfect. The S8 nozzle seems to be the best compromise if I don't want to fiddle with the Mikuni all day. I have no problem getting it real crisp with the S7. Now that I think about it, I have been running the Mikuni most of the time lately and the Keihin has been sitting in a box.
I'll take mine without a TPS please.
The only thing keeping these carbs from being 100% accessible in and around the frame spars is the length of the throtlle cable. It helps to route it correctly. But I usually have no problem twisting it and getting to the float bowl or the needle. I did have the Rad Valve on the 00 and it did push the carb back about 1/4 of an inch making it nearly impossible to get at the jets and needle. It also did little if anything noticeable for the performance that good jetting couldn't do...so Mr. Boyesen was nice enough to refund my money according to his satisfaction guaranteed policy. I will never again drop money on a reed setup.
I will admit that the airbox is cramped, and wonder how you can get a straighter intake without offsetting the shock? It is also a pain getting the engine out of that frame!!
Maybe the 92-99s were a world better and maybe these are the CRs everybody compares too. I have only ridden a 97 from that selection so I wouldn't know.