Yes a impulse mag would certainly help and is probably the ultimate fix. Try in the meantime turning off the fuel supply shortly before shutting down, 15-25 seconds at 1000- 600 rpm. This will drain the carb float chamber. Then when you are about to start the hot engine, turn on fuel for 10 seconds and turn off again. Start eng both mags, throttle closed then when engine runs don't forget to turn fuel back on otherwise within a minute you will have to re-start ! This proceedure seems to work on our C-85 when hot, although it is hardest to start when in between hot and cold..... good luck.