4 cell cat hull?

[Bande1]

Could I just have a bad motor?

doubtful. maybe a bad battery or connections. Running big props requires much larger wiring. go to the prop calculator and you will find that your speeds are perfectly inline with the motor and prop. In order to get +10mph you'd have to run about 75mm total pitch i.e. 48mm 1.5 pitch or so. If you go to 8s you can prop down dramatically (42mm) which will lower the amps and temps while getting + 10-15mph.

higher voltages are always more efficient in any and all electrical systems. You want high volts and LOW amps for max efficiency. when you run low RPM boats with big props you are pushing batteries and wiring to the extremes. Batteries can only output about 30c continuously. maybe 40c for really good batteries. So you need massive batteries sizes, at least 8awg wire, 6.5mm - 8mm connectors, and giant props..... all to go slower.

you have an 8s rated motor. run it what its meant for or get higher KV for 6s with smaller props.

[tjsb]

Thanks for all the info

Tom

[jkflow]

Thanks!
My motor overheats with those prop sizes, I can get maybe 2 min in without issues.