The energy of the hydrogen and carbon monoxide produced by the partial oxidation of methanol in the combustor located in the intake system of a S. I. engine was investigated in order to improve the cold startability of neat methanol S. I. engines. The range of load over which stable engine operation was obtained using the combustor was discussed by comparing this flammable gas energy with the energy required to operate the engine at -30°C. The test results show that the energy of a flammable mixture consisting of the flammable gas produced by the combustor and air is 500-850 J/cycle in the case of a 2L engine. The maximum energy of this flammable mixture is comparable to that required for no load engine operation, and so only no-load operation is possible using the combustor after the starting engine.