First thing that you need to do is run about 4 to 5 tanks of fuel thru this engine at about 4000 rpms to start the break in process. The engine needs to be run very rich at the beginning. After 5 tanks of fuel you can start leaning out the high speed needle and low speed needle. How much fuel have you run thru your engine? It takes about a gallon before you can get them to idle right. It sounds like you have the lowspeed needle to rich if your engine dies when you advence the throttle from idle. Try setting it back to the factory specs and start from there. Use a tach and set the high speed needle to the highest rpm that you can get. Once you get max RPM, back the highspeed needle off about 400 RPM. Next use your throttle trim to set the idle to the point that it will run without dying. Next advance the throttle from idle to full and see what happens. If the engine dies turn the lowspeed needle in about 1/16 of a turn and try it again. Keep doing this until you get a smooth transition from idle to full throttle. Each time you do this use your throttle trim to get the engine to idle at its lowest point with out dying. I have found that the lowspeed needle on these engines needs to be turned in quite a bit from the factory setting. These engines take some tuining to get just right but once tuned they are great running engines. I have about 2 gallons of fuel through mine and it just keeps getting better with every tank. Hope this helps.

Rick