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MacDuncan

FMF "turndown?"

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Learning all the time, mostly from SDAR moto folks.  FMF no longer makes a muffler for my 2007 bike. An attempt to fix is the next step since the high heat gasket maker red bonding attempt only lasted a couple months.  Apparently, in interior piece called a turndown has come loose. I do not know whats inside so I do not know where it became unattached. FMF rep strongly thinks that a previous owner repacked incorrectly and broke it.  Consequently, the end of the spark arrestor vibrates in and out of the muffler up to 5/8 of an inch.  Doesn't seem to be a big deal, have ridden it like that for awhile, but it would be nice to fix if possible.  Maybe a more serious Bonding agent?  Maybe a repack, and while in there, a small tack weld inside?  or a tiny tack weld from the back with spark arrestor out?  But, titanium is the name of the muffler, so is it actually titanium, and can it be welded easily?  I would need to slide the spark arrestor in still after the weld so there isn't much room to have a bubble in the weld that restricts the insertion of the spark arrestor.    I attached a pic with the spark arrestor out, and pliers holding the part apparently called a "turndown" that slides in and out a bit somewhat randomly.  The pic shows where the spark arrestor screws in with a small allen bolt, not to the exterior of the muffler, but to the turndown.  Any thoughts?  Thanks.

IMG_4252.thumb.jpg.863fcc9eedc1d57be525d268861f0558.jpg

 

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If I had to guess by looking at this example, I'd say this is made from stainless, which can be welded with non stainless wire (or rod). You just lose some of the stainless qualities at the point of weld. Still plenty strong.  

https://www.ebay.com/itm/FMF-Racing-040669-Factory-4-1-Exhaust-Spark-Arrestor-Insert-with-Turndown/122537470818?epid=202874631&hash=item1c87cd6b62:g:lyIAAOSwOyJX4LfM&vxp=mtr

I have a wire welder if you need some help.

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You need to remove the end cap.  Use a drill to remove the rivets if its riveted.  

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Thanks guys, Since I always use a metal bowl under my rolling chair, to collect all the pieces and parts I remove during a bike task.  When I dropped the spark arrestor in my bowl, it bounced out, and I remember thinking, that was strange.  So yes, likely the spark arrestor is stainless steel, so I grabbed a magnet this afternoon, and there was no sticking to the turndown or the endcap as well.  

So, Wildwood, good call. I may PM you again since Justin seems to mostly work on mild steel (like his nomadic racks).  Spaugh, thanks, but can I assume that you know that if I do drill out the rivits, and dive inside, that I might find some part of the turndown inside the muffler that is mild steel to steel, and therefore, more easily weld-able?

Anybody use JBweld in a situation like this (jb says to use only on areas less than 450 degrees.  Any thoughts as to whether the end of an endcap qualifies?  Thanks

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