I would richen the hsn. I followed exactly what the manual said and it wouldnt start. I went to 5 turns out and got it to start but not run without the igniter on. I then turned the lsn to 2 3/4 and that made all the difference. Last week I broke it in and have run 1 quart of fuel throughso far. The manual says after each tank lean the hsn 1/2 turnand after the fifthtank tune for performance. If I lean the hsn 2 turns my engine wont even move withoutspitting and sputtering and starting is not easy. Every engine is different there is nothing wrong with the engine. Like nitrosportsandrunner says you just have to find the right settings. If you get enough fuel it will start. To much fuel will flood it but I have yet to flood mine. I even hold my finger on the muffler until itfires then I remove my finger and next pull its running. I only have to do thiswhen the engine is cold. When the engine warms up it starts first pull. I do the same thing on my Traxxas Stampede. I have not read this any where but it works for me. Give it a try, be patient and get a roto start if pulling gets to painfull.