Is it the 21mm ?
Something i found about float level on the oko model
Check the float level by holding the carburetor upside down, angled over at 45 degrees. When the line across the float is just about parallel to the base the measurement from the base to the bottom of the float will be about 19mm. Originally recommended to us, we have found that the engine will flood when the bike lays over at this height. We recommend a float height of about 21mm from the base to the bottom of the float for best performance. At this height, the line on the float will angle up slightly from the base line. Use a pair of needle nosed pliers to slightly bend the tab the float needle is on to adjust the height