Here is an excellent 4-stroke Baja dirt bike carburetor for dirt bikes with 49cc, 50cc, and 70cc engines. The carburetor is compatible with the Baja DR49, Baja DR70 Dirt Runner, and the Baja Warrior WR49. Specification:
The mounting hole spacing is 1-15/16" (48 mm) center to center with 5/16" (8 mm) through holes.