How are you determining that there is no spark on #1?
3 weeks ago
2 weeks ago - last edited 2 weeks ago
It is best to to inject a strong solvent such as a carb cleaner or other similar product into a 2-stroke engine as they can strip away the protective oil film on the cylinder walls and bearings which could cause future problems or internal damage.
To clean the carbon use a product such as Evinrude Engine Tuner which is strong enough to loosen carbon on the pistons and rings yet contains a lubricant to protect the insides of the motor while it is running.