Not enough muffler pressure for it to pressurize the fuel tank properly. The Evo 10cc needs a little more muffler pressure for the carburetor to work correctly. Gasoline requires a very lean air fuel ratio mix compared to glow fuel and it only works within a very narrow air to fuel mix ratio as well, whereas glow fuel has a much more wide operating range for the air to fuel ratio in the engines. Thus the carburetor is more sensitive to that. That was one reason many engines use a fuel pump and a fuel pressure regulator in order to keep the air fuel ratio just right.

What might work Ok is to use the regular .46 AX MAC's muffler instead ofthe 55AX version. The smaller 46AX muffler would provide more muffler pressure. But I don't know for sure as I don't have one I could try.