I took the liberty to fabricate a replacement needle for the one Drone engine I got. It didn't turn out too bad at all. I left it a little long in case I need to move the needle in or out a little to get it to work at its best. I used a short length of .062 inch piano wire for the needle. I simply chucked it up in my micro drill press and used a Dremel tool with a grinding stone tip to grind the taper in the needle.
I was entertaining the thought of machining up a adapter with a carburetor to replace the screw on intake venturi stack. But much to my surprise the threads are a rare 5/16 x 32 size and thread. So I had to special order the tap and die from the UK. So it'll be a while before I can try a carb out on the engine. I think one of the .15 air bleed carbs that I have ought to work out perfect for it.
I also took a closer look at my first engine that I had bench run last week, and found that the spray bar was offset too far to the left, causing the little hole in the spray bar to be offset to the left, right on the inner edge. So that meant that the needle could not be screwed in all the way. So I readjusted it to center the hole better. I also went ahead and cut off about 1/8 of a inch from the needle holder so that there is less of a chance of it bottoming out again. In screwing it in or out, it is working much better now.
My new DIY needle inserted and soldered in place on the needle holder.
The needle valve assembly reinstalled back on the engine.
