In order to cold start the engine I still have to blow a bit of fuel in
through a sparkplug hole. I don't particularily facy this procedure:
remove cowling and a sparkplug, squirt gas into the hole, put plug back
in and cowling back on, and then start and go fly.

I have the two injection holes in the center housing blocked off. I'm
considering the idea of adding an electric valve between (pressurized)
fuel lines to carbs and one of those holes.

Anybody got a good source for a solenoid valve (closed when no power)?

   

Finn,

   One possibility on the cold start problem.  Even with an injector to
squirt fuel (regardless of air flow) into the intake runners, I have found
starting on cold mornings takes a bit of cranking.  When I had injectors in
the block it was no problem, but when I moved then away from the block the
problem on cold mornings be came a bit more problematic.  I suspect that
with a carburetor which is dependent on air flow for proper fuel metering,
low air flow during cranking might make it more of a problem.  Don't know
whether you have anything like an "accelerator pump" on your carburetor, I
suspect not.
So if you have low cranking rpm or possibly an air leak that would reduce
fuel metering, that possibly could contribute to the situation.

Regarding a solenoid, the Lycomings often have a primer pump for cold
starting.  In some cases this is manual plunge pump but they also sell
primer solenoids which are electrically controlled.  Check AirCraft Spruce.

Ed Anderson