It could be a blocked carb but it sounds more like a spark problem. I am assuming that you have the right gap on the plug. If you do it could be either the exciter on the magneto or the cdi unit. The bang is nothing more that unburned fuel exploding from a spark so you know that you have fuel and spark. The trick is now to get them doing what they have to at the right time. I would start with the cdi unit. They are quite expensive so take yours out and ask the dealer to try it out on another scooter before you buy one. They are a small bkack rectangular box with a connector with usually 4 wires going into it and you will find it either under the seat or in the battery box. If it is the exciter, let the dealer sort it out as it is a fiddly job.
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It could be a blocked carb but it sounds more like a spark problem. I am assuming that you have the right gap on the plug. If you do it could be either the exciter on the magneto or the cdi unit. The bang is nothing more that unburned fuel exploding from a spark so you know that you have fuel and spark. The trick is now to get them doing what they have to at the right time. I would start with the cdi unit. They are quite expensive so take yours out and ask the dealer to try it out on another scooter before you buy one. They are a small bkack rectangular box with a connector with usually 4 wires going into it and you will find it either under the seat or in the battery box. If it is the exciter, let the dealer sort it out as it is a fiddly job.