At –40, the only way my RX-1 would start is if I hold the starter on while engine is semi running. Even then it would take a few tries and make allot of noises. If I don’t keep the starter engaged while the engine is partly running, I’m sure it would end up flooding after to many tries. –40 is damn cold and the natural tendency is to not start and not have the desirer to ride. lol
I know its not recommended to run full synthetic oil in the RX-1s, but I’ve ran mobile 1 full synthetic 5-30 with no issues at all and I’m sure it helps in those crazy temps. With synthetic oil you really need to make sure you don’t flood the engine since having gas mixed in the oil really breaks down the oil if its synthetic.
Dan