Hi All
Generally all the motors from Hobbyking I have purchase came with the spider mounting bracket and screws.
All the motors I have purchase had the specs for the motor with required ESC, battery, power and all the required sizing.
Also they have water cooled motor mounts.
The 540 motor mounts handle the 35mm brushless motor, but, the red uni joints do not handle the extra power of the motors.
Banggood have a good range of metal ones(part No.87379).
I have not installed water cooling in any brushless motored boats as they only get very hot with over prop-ing the boat.
Yes I have done it, but, not kill a motor or ESC!!!
One of the problems is no specs on water prop size and loading for model boats!!!
Another is very limited specs on motors and required ESC's, also maximum voltage.
The SG is on my bucket list to build(I have the PLANS !!!), but, I have a few other projects to finish first.
Also one of the club member has two which he does not use, so, I am working on that angle at present.
Old buddy, old pal, old mate, fellow club member!!!
Including a water thrust tester which is one for my mad idea's and maybe a total failure!!!!
This also has a Watt meter, motor RPM, motor Temp, battery Voltage and thrust scales or weights.
Canabus