I'd been having trouble with my Ryobi conversion for the past month, it would run great for ten to twenty seconds, then start 4-cyclying. No amount of carb adjusting seemed to help, tried a different carb, still doing it. Then I remembered that I had opened the reed valve limiter a little. Close examination revealed that the reed was not completely closing any more. I rebent the reed limiter and it cured the problem. So if you've bent the reed limiter, view it from the side while holding it up to a light to make sure that your reed is closing completely. If it's not closing, hammer the section that holds the base of the reed flat, reassemble and check to make sure the reed is completely closed.