I have a 2010 WG, with Vance And Hines Big Radius 2 to 2 pipes and I have no problems with performance and love the sound level - loud but not obnoxious. Here's the problem. Last hear I had a flange bolt shear off for no reason anyone could come up with. Had have the bolt drilled out, and the exhaust flange reattached. Last Friday I had the whole pipe come out of the Exhaust port, with the coupling completely gone and both flange bolts being so badly rusted, they BOTH had to be drilled out and retapped. Now I know I was negligent in not noticing the deterioration before the failure. So my bad.

But here's the thing, the rear cylinder hasn't been touched. On inspection, the flange and bolts are oxidizing after three years of riding and 22,000 miles but they look fine. I guess I'm just asking if anyone (especially those with V7H Big Radius pipes) has had the same experience and/or some explanation of why the front cylinder/exhaust port seems to be having this problem? If so, anyone have any suggestions on how to prevent or delay problems in the future?

Any theories would be greatly appreciated!

Thanks,

USMAMule

 

A couple thoughts:
When the pipes were installed which were tightened first: trans mount bolts or head/flange bolts? It's important the head/flange bolts be secured before the trans mount bolts as it helps prevent misalignment of the pipes. Everything should be taken to finger tight and pipes should be "jiggled" to make sure they are aligned, then tighten head/flange.

Which flange bolt? The one that is difficult to use a socket on? Maybe it was not tightened properly? Just spitballing...

I never had any issues when I had my V&H BR 2-2, so I cannot think of any actual pipe related reason for this issue.

 

Maybe periodically try brushing on some Naval Jelly or other rust prevention/inhibitor when the motor is cool ...

Maybe use some VHT paint on the studs ... might be kind of hard to get them since I've only seen it in spray form ...

I've heard of guys using a second nut to prevent them from backing off ... I would think the second nut would also reduce the amount of stud exposed to the atmosphere ... and thus have some preservative effect ...

Just a couple of thoughts ...

 

When I installed my 2 into 1, I installed new studs along with longer flange nuts.
They do a good job of covering the entire thread.
Easier to wrench too.
When you ride in the rain you find all kind of things to improve on.