Recently my engine started acting up. It will start cold and run normally for maybe 10 seconds and then die. If I give it enough throttle, it will run, but the rpms cycle up and down. It seems as if the bowl is running dry, then partially filling continually cycling between dry and partially filled. I don't know if this the case, it just seems that way. I have recently replaced the ignition coil and plugs. It has a new fuel filter. I took carb apart and found a little trash. I cleaned it up very well with carb cleaner and blew out all the passages. No help. I haven't put a kit in the carb yet. Any ideas?