Hi Wayne:

Unfortunately, to get the brass insert, you have to get the whole carb body. Fortunately that is only 8 or $9.00. I put the brass insert (spray bar) from my good engine into the carb of the engine that was not running right. When I first tested it like this, it would not transition well in vertical flight. I had wondered if it was due to the below freezing temperatures, as a friend with a new O.S. .46 AX was having the same problem in the cold. Since in full throttle, vertical flight, the engine ran well, the only way I would know if the difficulty in a hover was a real problem, was to fly in temperatures above freezing. The 47 degree weather was perfect for that, and it proved the spray bar to be the correct fix.

No drilling was done on this spray bar at all. The hole was just spaced further away from the needle valve. I believe I listed the rough distance from the hole to the shoulder of the insert in another entry, but in simplest terms, it was more centered on the nipple. Looking at the port where the nipple screws in, the entire whole in the insert can be seen, rather than just the edge. The undercut is irrelevant. While it is helpful at lower rpm, at higher RPM, the flow is so fast, it can't make that sharp turn, from the end of the nipple to the hole in the insert, without turbulance impeading the flow. I believe that the fuel may not be entering the spray bar on the taper of the needle either, though I haven't tried to measure that. If the fuel is entering on the flat of the needle, or even on the transition from the flat of the needle to the taper, I believe the adjustments would be very touchy, if not impossible.

I hope I cleared that up, if not, let me know and I will try to write it another way.

Andy