SherryBerg Carburettor FCR39 FCR 39 Flatslide Carburetor FOR KTM XR DR KLX KLX400 DRZ 400S 400S 400E. Replace carburetor for fcr 39mm racing carburetor, replace your old KEIHIN, the aftermart carburetor good quality, NOT the KEIHIN. The carburetor is currently fitted with 55mm airbox adapter to suit Suzuki DRZ400-E model.