Hi Daniel,
A couple of extra tips from a fellow club 500 racer, that are within the rules.
I would agree with fixing the flexi coupling, but this can cause another problem that is not always obvious.
If the boat has a front end impact, the inertia pulls the motor, coupling and shaft forwards. This can cause the thrust washer or nut at the prop end to bind on the prop tube, and causes drag. The effect is a slower boat and reduced running time.
To stop this happening, I fitted an aluminium plate to the back end of the motor housing using one of the two mounting holes which are not used to hold the motor. This then sits behind the motor mounting bracket and stops the motor going forwards after a collision. It is also essential, in my opinion to line up the motor coupling etc before fitting the deck, as access is limited to the front. It is not possible to over stress that the motor and shaft must be in perfect line. Failure to do this will result in a slower boat. This is a controlled class, and the only way to win, is a perfectly constructed boat and good driving.
Secondly, the rudder assembly will benefit from an easy mod. It is fitted into what I call the top hat assy.
This piece is glued to the hull, and then the rudder tube fits through it. This causes the tube to compress the hull. If not tight enough it will leak, if too tight it will , after a while, crack the hull. All I did to prevent this was to fit a second tube inside, so as the rudder tube is tightened it acts as a spacer between the hull and underside of the top hat. It must be the exact inside length or it will not work.
I will not blow my own trumpet, OK I will then, I was Club 500 world champion of Bridlington, for three years running,
and if you visit our Web site you can see build instructions and tips for Club 500 boats.
Bob
http://www.fastelectricsrfun.co.uk/club500/CLUB500.htm