This front sprocket is used on the Chinese 200cc engines, specifically the Coleman KT196 and the HiSun HS200GK go-karts. May be used on other applications as well. This sprocket has 25T and is compatible with the 420 chain ONLY.
Sprocket details:
#420 chain
25 Teeth
ID 20mm [.78″]
OD 106mm [4.16″]
Four 8mm bolt holes 26mm [1.02″] apart center-to-center side-by-side
Bolt holes are 37mm [1.46″] center-to-center across from each other
Be sure to measure your chain or current sprocket before ordering. 420 chain has 1/2″ pitch and 5/16″ roller diameter. Most Chinese sprockets have the chain size and teeth count stamped into the metal.