I tried a Norvel on a Yvenko, it was nuts tail heavy!!

I can agree with what you are describing.

       Dave, I have used with good success the needle spraybar assembly from the Cox production backplates. I've pressed the spraybar out of the plastic and soldered a piece of 3/32 tubing over the hole in the spraybar. Some of the older ones and a lot of the cars used these backplates. They had what I believe was the 125 thread per inch needles. I found a lot of these to be the red style backplates. Those needles are similar to the Kustom Kraftmanship needles used on the Tee Dee engines. I just file a little fish mouth on the tubing prior to soldering and be careful not to get solder in the hole. A little creativity is needed to attach to the plane but its effective and cheap. Dale Kirn used something like this on his 1/2 A speed planes that were running on bladder. I saw this idea used in 1980's Model Builder mag. I have even made a nylon insert that fits into the bathtub venturi hole of the Norvel case. Its drilled and tapped for a Tee Dee venturi which uses a fine threaded needle. The engine runs very well and starts with ease. Ken