I recently purchased this engine from a guy who upgraded to a brand new 4-stroke. He said he had a mechanic replace the coil and float. Also he cleaned out the tank and carb all last sept. It has run in a barrel once since. When I start the engine after making appropriate adjustments as stated in the original operator manual, it idles fine but starts to back fire or spit back. If I engage the prop and rev the engine it runs fine. If I leave it at idle speed it will eventually die because of the backfire/spitback issue. I tried adjusting the slow speed needle to make the engine run richer at idle since it sounds like this was a lean "sneeze." It does it regardless of how far out the slow speed needle is. I've resigned to the fact that i'm going to have to take the carb to clean it out again, anything I should/need to look for while i'm doing this? Is there an air adjustment for the slow speed intake?
