G4-7 atwood water heater lights great, heats water but when it cycles the pilot goes out no hot water

Sounds like the burner flame may be too strong (jumping out from burner tube) . Some people think the louder the better, but that is not correct. When burner shuts down like that, it has a tendency to snuff out pilot as well. Adjust your air shutter at burner so that the flame is a nice blue, or with just a hint of orange/yellow at the tip. Whatever setting that keeps the flame solid from burner tube, and not a big gap between tube and flame. Signs of soot (black) up the cover, or side of trailer means it's running too rich, and you've gone too far thus needs more air. Keeping the flame blue but still right out of the burner, actually heats better, is quieter, and should eliminate that pilot getting snuffed out. Pilot should also be a nice blue flame as well. There may be a problem with positioning of the burner tube as well, but doubtful if it has been running well in that position before. Let me know what happens.