Originally Posted by
1967brutus
I Something that COULD be an option, is to make valve housings with a threaded part that would fit into where the NVA screws into the carb body. It would maintain any possible airbleed or LS needle the carb allready has (solving the issues with idle stability), it would look "nearly the same" but again: not every manufacturer uses the same thread size for the NVA, and the absence of an orifice such as Chris and Rob use still would be a possible issue...
Unscrewing the needle valve holder and screwing the solenoid holder in place would make for a simple low cost conversion.
You could even go as far to include a small screw to plug the fuel nipple hole and reuse the nipple on the solenoid holder.
O.S. appears to use the same size holder on a whole range of carbs for both plane and heli engines.
What could be done is have a 2 part holder design.
The (possible delrin? )cup that holds the solenoid would be the same for all and then pressed into that a (bronze?) tube that is made to fit the original needle holder.
Thinking of it a bit more why not reuse the needle holder too?
Make a cup design that the needle holder has a snug fit into and secure it with a setscrew from the side.
A small "O" ring inside for the holder to press against should avoid any air leaks.