I have a 10 yr old blower that has been a pretty good machine. Last fall I replaced the carb kit as well as new fuel line (was cracked) and had trouble running. I used after I was done and it ran great as well as several times this summer,However now that I want to blow leaves it will not stay running. It will run 10-20 sec then just shuts down. I put new gas in it and it still does the same thing . I have an idea it may be a faulty ignition (kill ) switch. any help would be great .