I have a question regarding installing a new Arlen Ness Petcock I bought for my Sportster.
It has a large nut on it that is threaded normal where it attaches to the tank and threadedreverse where it threads into the petcock. It didn't come with instructions and I am not sure if I installed it correctly.

What I did was unscrew the largenut from the petcock until only a few threads were holding it on. Then.. I took the entire assembly and screwed it into the tank by tightening the large bolt clockwise onto the threads of the tank. While tightening the petcock itself was being drawn up to the nut because of the reverse threading. The problem I thing I have is that even though the nut is tight against the tank, the petcock can still spin when force is applied to it.

Is there a trick to this?? Thanks in advance!!

 

You just need to loosen it from the tank and screw thepetcock in a little farther and then retighten you may have to do this 6 times before you get it in the right spot .
The idea behind this set up is you are suppose to hold the petcock with the not tighten nut up to the bottom of the tank and by turning the nut you tighten both at the same time.
I know that's as clear as mud but that's the only way I can think of to explain it.

 

Listen to this guy, he knows wtf he's talkin about,

 

Hehehe... petcock.