Previous studies on poly(m-carborane-disiloxane-diacetylene)s established that the representative polymer 1, having the carborane, disiloxane and diacetylene moieties in a 1∶2∶1 ratio in its repeating monomeric unit, exhibited plastic characteristics at ambient temperature. In this study, the diacetylene-diluted variants of the above system were synthesized and thermally cured to determine their elastomeric properties. The resultant diacetylene-diluted polymer variants 4a, 4b and 4c, where the corresponding ratios of the constituents were 2∶3∶1, 4∶5∶1 and 9∶10∶1, were determined upon curing to possess Tg values of 56 °C, 45 °C and 35 °C, respectively. Even though the diacetylene dilution resulted in the lowering of the Tg values of the new systems, they were still found to possess predominantly plastic characteristics at ambient temperature.