Gotta good running la 46 that is becoming hard to start after the first run, it starts well first run, but has to be primed thru the venturi for all other runs.
  It even sits between runs for 10-15 minutes.
 Any idea's or suggestions?
 Oh, I am using 5-10Nitro, 22% oil half/half, thunder bolt plugs.

  Again thanks a lot...

Gotta good running la 46 that is becoming hard to start after the first run, it starts well first run, but has to be primed thru the venturi for all other runs.
  It even sits between runs for 10-15 minutes.
 Any idea's or suggestions?
 Oh, I am using 5-10Nitro, 22% oil half/half, thunder bolt plugs.

  Again thanks a lot...

   They are the hardest to start when they are at an intermediate temperature. When my buddies and I go flying, we fly two flights back-to-back (to save time moving airplanes on and off the circle). The first flight (after having sat in the pits for an hour or so), no problem, always works. Second flight is also no problem, if you *immediately fill the tank* and start it (~3-4 minutes). If you get distracted or have to change something so it has been sitting for around 8-10 minutes, we will frequently have a problem, which usually involves extra priming and flipping to get the temperature equalized.

    What is happening is that if you fill and launch right away, the cylinder has cooled slightly but the piston is still hot, so the fit is reasonably tight and easy to start. Depending on the engine, you can either start it immediately with no choking  (PA) or at most one or two chokes (RO-Jett). If you over-choke it, the fuel gets on the piston and shrinks it. You can feel the compression go away. Then you are in trouble. The usual solution is to remove the battery and flip it forward a bunch of times until the temperatures equalize. You can feel it getting "poppy", when it feels right, hook it up and back-bump and off it will go.

   At intermediate temperatures, it's not hot enough to fire with no choking, but it's still hot enough to not have compression if you overdo it.

   I would suggest changing your flight timing (fly back-to-back to get less "off" time, or go in a cycle with your buddies so you get more "off" time). Ultimately starting engines is about getting the right technique.

   BTW you are probably getting some varnishing that will likely make it more difficult. Use RO-Jett fuel or something like SIG SYN-Power for a gallon and see if it changes.

      Brett