I'm having a bit of a chuckle reading some of these replies. How many people have crawled around under their motorhome and had a good look at the gas tank and associated plumbing?
Want to siphon some fuel? Go ahead and give it your best shot. On my Bounder there's about 15 feet of plumbing with 3 90's and a 45 bend, the straight sections are steel pipe, the bends are rubber. There is no anti-siphon device because it's simply not needed.
Poke a hole in the tank with a knife? Again, go ahead and try. RV tanks aren't stamped sheet metal like you'd get on your daily driver. I dropped my 80 gallon tank when I changed the fuel pump: it's welded steel and it's heavy. The best knife you've got might scrape some dirt off.
As for drilling a hole in the tank? I would think that anyone dumb enough to consider using a power drill on a full tank of gas would have already removed himself from the gene pool.
Cutting the generator fuel line and siphoning from there: you're assuming a high degree of technical knowledge specific to RV's, which is something most RV owners don't even have.
I've never had a locking cap, in all my years of RV'ing I've never had anyone try to steal gas.
If you have legitimate cause to think that someone might add something to your tank: get a locking cap.
I'm not trying to insult anyone but many of the questions that people ask on this forum could be answered by simply having a look at your rig.
1994 Bounder 32, F53, 460
