My Ms280 wouldn't start, found the issue was no spark with new spark plug. I replaced the ignition coil and gapped it. saw started right up and ran well for about 10 minutes. the it would run but not idle. I restarted it a couple of time but it would stop when I tried to idle it. then it stopped and now will not start. also now it has a significant amount of resistance when I try to pull the starter cord. Has new fuel and plenty of bar oil. Thanks for any help!