Swapped my Huyai carb on the Hisun for the PK2B of my Tillotson to see if I could find something. Might have found a little power by the butt dyno, but had a hard time dialing it in perfectly. Maybe the pilot jet is a bit too big. Not too surprised. The PK2B is just supposted to be built to tight tolerances, not necesarily performance enhancing.
Got my PVL flywheel in, lapped it and mounted it with the 5 deg key I had on the stock flywheel. I think the 5 degrees in addition little bit of built in advance in the PVL was a bit too much. No kickback, but it was a bit harder to start and didn't seem to run as strong, so I reset it with a stock key. I filed around 2-3 degrees off of a key to try, but haven't put it in yet.
Wheelies are back! The lighter weight flywheel must spin up quite a bit easier than the stock one. I'd like to see aluminum flywheels promoted as a performance enhancer, not just a safety tax. Just the flywheel alone got the Hisun a lot closer to the Tillotson than it was before. Blipping the throttle and jumping little dips and humps is of my favorite things to do when I ride. Neither the Tillotson nor the Hisun will do it if you are going over 5-10 mph or so, but if you are crawling through some tight trails, blipping away is a blast!