28mm flat-slide carb....

even a mildly portedengine will be useless in traffic or if you rely on it for getting to work an so on. a full bolt on setup will see 23-24bhp anyway wich will go for hours no problem

the carb should fit in the malossi/polini manifold and you can drill a hole for an oil fitting so you need not run premix if you prefer to keep the pump