If the scooter bogs or won’t idle, clean the pilot jet. The stock carb is a Keihin PB type.
Change the plug every 5,000 km. Clean the foam air filter with soap and water, then oil lightly. service manual honda sgx 50
Recommended every 8,000–10,000 km. Symptoms of a worn belt: sluggish acceleration, squealing at startup. If the scooter bogs or won’t idle, clean the pilot jet