Starting the Yak 54's M14PF radial engine is a bit of a workout . A lot of blades need to be pulled through to ensure there is no residual oil left in the lower cylinders and it involves a lot of priming to ensure a combustible mixture is present. On top of that it needs pre-heating during winter time..
Nevertheless every time it finally rumbles into life it is worth it! ;)
The reason for this meticulous procedure is the starting system. The starter is driven by pressurized air, however to save weight the Yak 54's pressure bottle is minimal in size. In result you only have 1 -2 very short attempts before the system would need a refill from an external source and that's why you want it to be able to start immediately.
