I have been dialing in my modded XR200R. Love the way it handles with the 1987 suspension with Race Tech Emulator fork kit and Progressive suspension fork springs and the Works Performance Heart Transplant. I had to split the cases due to the engine jumping out of gear under a load so I had Wee Racing in Alabama and Powroll , mod the engine with a stroker crank, 66mm 10.5:1 piston and the FULL RACE cam. We built a 1.25" header and are using the stock muffler with the large diffuser insert (ATC250R). Wee Racing specially degrees the Cam advanced to improve the low end and midrange. Powroll says it won't work but Chuck and Brad at Wee Racing have been doing this for many years with great results. They claim it is reliable also. We are using the stock carb. So far I have had to drop the main from the 130 they installed to a 122 and may drop to a 120. Stock needle in the middle position. Right now I have the stock 38 pilot but my fuel mixture screw is set at 1/2 turn out and probably can go in more so I will change to the leaner 35 pilot. It still has a bit of a blubber at 1/4 throttle. I think this is due to the engine now (with stroker and BIG cam) drawing hard on the smallish carb at low throttle openings. I currently am running stock 13/47 gearing but will be changing to 14/47 as it feels way too low geared now. I am running stock rear wheel with the stock IRC Ve33 tire which works great. I will keep y'all up to date with testing and how it works. This is my Post Vintage Race bike, Backup modern race bike and Enduro work bike.