I've got a suzuki JR80 that I use for cruising around my property as a pit bike. It recently started to pop and backfire randomly and now it is physically not ride able because of the popping. The bike still starts up first kick and will idle but as soon as you twist the throttle it will pop/miss and then backfire out the exhaust. Once it backfires it usually stalls the engine. From research online I've heard that most of the time when a 2-stroke does this its a sheared key on the ignition. I popped off the ignition cover and all looks to be well in there. No metal shavings and I can still see the key intact. Could it be a bad coil? Want some guidance here before I start buying parts. And no I haven't checked the compression yet. The top end has less then 5 hours on it.