Pro Boat UL 19 battery + upgrades

[jkflow]

Don't do the dual rudder, won't help you with overheating. Install a transom water pickup instead, plenty of water.
Seen many people do the dual rudder pickup, and they don't achieve anything but having a cooler ESC while the motor still overheats.
Stock prop is good, just a matter of cooling things down.

[RMac]

Thanks for the advice on the cooling. If I go 6s what would be a safe prop size? the original is 43mm with 1.6 pitch. Im looking at the Octura props and there's seems to be and endless number of options in styles and sizes. Trying to do my homework ahead so I don't burn anything up and learn the hard (expensive) way.

[jkflow]

There is no right answer, what is your motor kV rating? That determines the rpm and the best prop size.
kV= rpm per volt (4S=15V, 6S=23V rounded)
Try the stock prop, see how hot it gets after 2 min (max) and go from there.

Motor should be in the 1600-2000kV range.

[RMac]

Got my UL-19 and have been running it with 6S and the stock prop but I added a lot of cooling up grades including duel pickup rudder, a flush mount pick up on the bottom and a small water pump to keep it cooling running and even when stopped. Also changed out the ESC for a OSE Raider 150. Still running the stock a3650 2000Kv motor. I ran temp sensors on the esc, motor, and in the wiring. Temps top out around 110 even when running WOT for the motor and esc however the wires run a little hot at 120 to 130 but I can trim some length out (about in half o 3 to 4 inches) and should be able to reduce that heat there quite a bit. Question: I have an extra spectrum Firma 4074 2050Kv 4-Pole Brushless Motor, would there be any issue with running it on this set up? And if so would I need to change anything up? The specks are below and it is quite a bit more motor then the original Dynamite 2000KV. It's and extra motor laying around and I would like to use the Dynamite in another boat if this Spectrum will work in the UL-19?
Second question? if the Dynamite spec below shows 680w of output power at 7.2V. would that mean running it at 6s (22.2V) its output is roughly 2000w?

Spektrum Bearings
4mm Bullet
12.6–25.2V
Brushless
5050W (6S)
2.9" (74mm)
Spektrum Firma 150 Smart ESC 4074
10 AWG





Dynamite
RPM/VCurrent (A) at 7.2V Dimensions (Dia. x L) Weight
Efficiency
Poles
Power
Shaft Dimensions (Dia. x L) Turns
Voltage
Connector Type
Maximum Timing

2000Kv
2.3A +/-0.8
36mm x 56mm (1.42 in x 2.20 in) 294.8 g (10.4 oz)
92%
6
680W
5mm x 15.5mm (0.20 in x 0..61 in) 1.5-D
7.4V–22.2V
5.5mm bullet
7.5o