Keihin PWK 28 carbs are found on most high end 2 stroke trials bikes from Gas Gas, Jotagas, TRS, Sherco, Beta and Scorpa
Pilot Jet size affects the fuel/air ratio in the first stage of throttle movement.
Genuine Keihin Jet, not cheap copy. - pilot sizeing is critical, don't be caught out be cheap copies!
Available in sizes: 35, 38, 40, 42, 45, 48, 50, 52.