Have you checked that fuel will flow through the needle valve assembly?? sometimes crap gets blocked in there. Unscrew the needle valve all the way out and remove it . Hook up your fuel pump to the fuel intake for the needle valve pump a little bit of fuel through it. You should see it coming out where the needle valve was. Make sure there is nothing on the needle valve itself too. Put it back together and try it again.

Also, instead of "priming" the carb by putting fuel into the air intake try this. WITH THE GLOW STARTER REMOVED, open the throttle to full, place you finger over the air intake on the carb, turn the prop counter-clockwise, each time you turn over through the compression you should see fuel moving up the fuel tubing, keep turning until you see fuel actually going into the carb, turn it over 3-4 more time, remove your finger from the carb, turn it over 3-4 more times, move the throttle to idle, place the glow starting on the glow plug, and start the motor. Priming the motor this way will ensure that is actually drawing fuel through the fuel system, and there will be no lag after the motor starts.

Hope this helps.