just got a CEN 775 Grey Thunder today and took it out for a spin.... when i took it out of the water the motor started revving all on its own the radio controller was still on 5 feet away, when i pulled the cover off and switched the boat power switch to off the motor continued to revv at a very high rate

Could this be a short from the motor to the batts?

It is brand new and looked good dont see ant areas where it could short, but when it comes to electronics my wife wont even let me jump the car battery..

Being a newbie and non-electrical smart what could this be.

Other facts two 7.2 batts each 6 cell, 3000 mAH Ni-MH

sounds like maybe a fried esc. try a known good esc. thats where i would start.

Did you get water in the hull/radio box?

What would be a good esc for a stock CEN grey thunder? Also how would i have fried it...the batteries?

I ran it for maybe a total of 5 minutes, the only water was two very small droplets directly where the rudder rubber cowling is, nothing near the rest of the engine bay, I taped the whole top down and had a towel covering the whole compartment.

What exactly is hatch tape, and where can i get some, is there any special silicone spray for the esc and other components?

Im sure ive got a million questions, but i appreciate any and all help, thanx!

Does the esc run a receiver pack(4 aa batteries)? Or does it have BEC? I remember reading somewhere that some on and off switches only turned off the receiver leaving power to the motor still. Its always a good idea to unplug the batteries first then turn off the switch. If everything still works normally with the switch on (motor turns off and on by throttle control) the above maybe your case.

People use electrical tape or plastic hockey tape for taping hatches because it's more flexible than hatch tape and cheaper. I also think that hatch tape tends to ruin decals or even the finish of the boat.

Check my ad if you need an esc

I guess its a BEC (what is that?) because the only power would come from my 2 7.2 batts, if i were to upgrade my controller ive seen that the FM ones are better, is this due to better protection from interference? is there any performance reason to upgrade the esc if nothing is wrong with it?

I just got done prepping the boat, paint, filled the front with the expanding foam, getting ready to coat the interior of the boat and components with some Boeshield T-9 spray, does anyone know if the would interfere with anything, and if so i also bought some di-electric grease to cover the esc and servo stuff. I want to make sure i keep it dry, Im going to be running in sea water 90% of the time so i want to make sure corrosion is avoided.

For tape is just plain old invisible tape good enough?

Thanks for your help, and from now on ill unplug the batts first

J

BEC means "battery eliminator circuit". The receiver takes it's power source (5-6V) from the ESC instead of from a separate receiver battery pack. The only way to be absolutely sure the motor won't start up on its own is to disconnect the batteries. They can randomly start from time to time even when the receiver is turned off. Keep your fingers away from the prop if the battery is connected. I wouldn't conclude that your ESC is defective right away. If it continues to be a problem then maybe it is.

Greg

Ok thanks Greg, paint is finished and the waterproofing is working ran it today and had a blast. I pretty much covered everything with di-electric grease and had no "lil gremlins" pop up so hopefully it was just some moisture in the components.

If moisture is the case then let the components dry out for a day or two.
When my 30 inch hydro flipped during a run, the whole thing was filled with water to the top, but after a day or two of letting everything dry, everything worked just fine.(except the esc cuz it wasn't waterproof)[sm=frown.gif]