RC Tank Warfare community hobby forum

Well, I resolved the slow/non-running smoke unit by simply bypassing the circuit board on the unit. Seems to work fine now. However, looking at photos of these smoke units I see that some have a small square circuit board with 2 resistors fitted and some have the same board without the resistors. Looks like the resistors are in the supply to the pump motor. Presumably the resistors slow the pump motor - but why is this necessary?

BTW, thanks for all the help received here! I'm just waiting for new gearboxes from Forgebear Tanks then the Tiger 1 will be going back to my friend in full running order