RE: More lapcat2/7.5 kb probs
The problem sounds like it my just be your throttle cable. Send a pic of that. It has to be hooked up on the motor block usually with a clamp. Even if you have that, sometimes those loosen. Check at the radio box too to see if the cable tube is attached there.
If you do have problems with the prop nut coming loose, add a piece of larger fuel line between the prop and nut. I haven't lost a prop yet on any of my boats by doing this.