Modified Stiletto project
I had the same problem with the Russian work boat, and solved it by using another smaller 3ch RX and plugging the sound unit into the throttle on that. Found with this ESC I don't have that problem, so won't need the other RX. I fitted 3 capacitors to the pump motor, plus a ferrite clip on sleeve to its' power lead, but not sure if it was that or the different ESC which did the trick, but the capacitors had to be a good thing anyhow.
Motor is not as smooth with this ESC, especially at low throttle, - sounds like the timing needs changing so will need the programming card to see if it can be done, (doesn't appear to have the normal manual setting mode,- no instructions for that anyhow.) Most ESCs have the same method of entering the menu, but doesn't seem to work on this one.
I have another few motors I can try which might be smoother if this one gives problems,- 2 nice smooth 1500 kv heli motors with built in fans,- but they might be too fast.
Re the cooling fan which comes fitted under a cover on the new ESC,- this runs constantly with the power on, so I have interrupted the fan power neg lead from the micro JST plug on the ESC, and screwed a 30C thermo switch to the side of the heat sink, so it will now be automatic on-off, and won't waste battery power when sitting still. I don't anticipate things getting too hot with the motor I'm using, so it should do the job.
Still a bit noisy and coggy, but it's not possible to easily rubber mount a motor and keep it lined up. Now need a nice calm day for the test run, (airboat rescue boat will be on standby😉)
JB