I run an OKO 30mm (Keihin PWK30 copy), but i have also run a Polini PWK28mm, the flatslide carb's are very touchy/responsive and seem to give me a better top end compared to the Keihin PE28
the flatslide / d-slide's need more cable hanging out the end of the outer, approx 150mm of cable hanging out the end out the outer casing
This is one a local Aus seller has
Check these guys out.. Great prices and tells you all the specs for each carb. Seems like the smallest TM series carb thats a pumper on there is a 33 though. I dont think the 28 is..