The amount that the needle valve is open is fairly critical to getting the engine to start and run properly. The Saito manual says screw it in all the way and then screw it out 5 full turns. Saito always has you set the needle valve too rich so I would start with 4 turns out at most. That should be good to get it to start but be aware that you will likely need to close the needle valve (turn it clockwise) to get the engine to run well. If you don't have the manual for the engine, you can find it on-line with a simple google search.