broken muffler pipe ??

[jloi]

Hi.  Can anybody tell me if I might have  used wrong gasket  or could it just have been mounted crookedly and that put stress on the pipe and broke it or if the  home made gasket was leaking  and maybe  it got hot and melted  or became weak ?  ( even tho I never heard it being loud )  ?

 I put a new muffler on the gy6 150 a couple  of days ago with a gasket I made from  this -   Mr. Gasket 5960 Ultra Seal Exhaust Gasket   --  www.amazon.com/gp/product/B000BWAPHA/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1  . 

 Yesterday I drove about 20 miles + or -    and I got about 200 yards from  home when all of a sudden  the exhaust got  loud. I figured the gasket failed . Today I looked at  it and saw that the  pipe  itself  was broken right at the flange  where  it connects to the  bottom of the head. I removed the stud  nuts  and disconnected  the  other end  of the  pipe from the  muffler and  the  pipe which was already  loose  fell  off  and so did the rest of the flange; which you can see  laying there .  It doesn't  look melted , it  just looks broke.  I looked it over real good and I don't see any signs  of  it being melted

 It seems  to me I must have  put the whole muffler and  pipe  on crooked and created a lot of stress  on the flange; but  I was careful to make sure I had the flange of the  pipe  flat and  tight to the head  before I tightened it   completely.

 

 What do you all think about  my using this gasket  material to make a gasket ?

 can anybody tell me  what  might be wrong here .

The  previous  muffler developed a leak so  that's why I got a new  one .

Ever since I put this new  motor  in I've  been hearing a slight  puff through the  muffler . That's why I   tried a different gasket . 

 Also can anybody tell me  if I should be  using the round  copper  gasket  for the head  before the  flange  gasket  goes  on and  if so does  it go copper side to head or copper side to  pipe/flange or not make a difference .

thank you

[jackrides]

Some observations: the larger gasket surface does not look uniformly compressed; if the copper ring fits correctly, and one side says it does, the large gasket is unnecessary, pic of the other side of the ex flange might help; is the other side of the flange absolutely flat?; the weld looks inadequate to me, but a real welder needs to advise on that.

[jloi]

Thanks .  I'm pretty sure  I know what happened and  how to not do it again .  When I get the new  pipe  I'll put the  pipe to the exhaust   studs first , leaving  it disconnected  from the  muffler. Once  I have  the  pipe  relatively  very tight  ( secure )  then  I'll  align it with the  muffler flange  and see  how it  aligns with the swing arm brackets/posts  making sure everything  lines up easily and without any stress on any portion .

 There was an  imperfection /bad place  on the gasket I used   and I won't repeat that; but I'm pretty sure  I just had things  misaligned and that caused stress  on the  pipe at the flange / head and  that's what caused it to break .

 The  info I got about the copper  gaskets is that they are only good for  one time  use  because they get crushed  in the  process  of tightening versus  the  thick silver gaskets can usually be used over again a couple  of times.  also they aren't used together. I'm gonna go back with the  thick silver gaskets  and see how  that works .

 

 You can  only see the  weld  on the flange from the  other side so there are no weld marks  on the  pipe itself  since  it broke  off  on this side  of the weld . 

 I never had any problems  with the  old engine   and  the muffler etc .  I had the  pipe and  muffler  off several times  and  it always  went  back without any  problems at all and  it never  leaked  . 

 thanks  , I appreciate  your  input.