I had the same issue. Contacted Horizon and didn't get an answer. They couldn't understand the problem. I went online here and did not get an answer. I finally used nyrod and a very large bend to get it to work. I constantly have to fiddle with it to keep it working correctly. Chocking is another matter. I finally gave up on any solution and just use a starter to spin the motor, prior to starting, for about 5 minutes to pump fuel to the carb. Then it will start. I like the way this engine runs, it has plenty of power, but Horizon really should redesign the carb abd linkage problem.
steve