Hey guys I posted this in the Honda 31 thread. I did a GX31 a while back. Still no plane for it but I did experiment with carbs. I drilled the case for a pulse tap and ran a WT carb so I had 2 needles. Ran great but the tube will clog after an hour of running. Found 2 WYK 2 needle carbs that worked. A WYK-61 is a 9mm carb and a WYK-137 is a 10.5mm carb. The 61 was the first and to date only one I tried. Ran a strong 6400RPM on an 18/8 Zinger prop. Instant transition plenty of top end power and a snap back to idle. Just made a flange and a straight tube maybe 6 inches long for the exhaust header for now. Putts and purrs! I intend to make a different intake manifold to rotate the carb linkage and have a larger bore for the bigger WYK-137. I also removed the compression release stuff on the cam as it will hold the vales in certain instances and cut power when you least want it to. Also run it on a CH ignition. Works like a governor it seems. May also try an 18/4 or 18/5 or a 20/5. Don't need speed but I want to increase the torque if I can for a WW! plane. Hope this helps.