Singer motor testing finished today pulled a full 18 amps max load with 125 mm prop, 5-10 amps normal range was hot to touch but not that hot to burn ran from 3 volts to 18 volt best was 6-12 volt range, noise was the same as a 540 5 pole at noise props from 50-125 mm all ok took 22 hours to drain 12 volt battery 10 amper cooling pump kept it at low temp 22degree to touch runs same speed fwd and reverse with little spiking and current drain in reverse.Very happy with these and off to buy more,the large cooling cage around the motor is idea heat sink well worth a try for large war ships /tugs stacks of grunt and at the right price for fellow modellers tassie48.