What if you used the priming solenoid with an injection just behind the carburetor, or other desired locations. Connect the solenoid to a switch that only can be hot if the starter switch is hot. When you want prime, flip on the switch and when you engage the starter, the fuel flows and when you let go, it stops. Flip off the primer switch. That also gives you a safety factor that you will most likely not accidently engage the primer while in flight, and that you will not be dumping fuel in a place where it has no where to go.
See N64KR at http://KRBuilder.org - Then click on the pics See you in Mt. Vernon - 2006 - KR Gathering There is a time for building and a time for FLYING and the time for building is OVER. Daniel R. Heath - Lexington, SC