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CVO Technical => Intake/Exhaust/ECM => Topic started by: HotRodFXR3 on August 09, 2018, 10:31:23 AM

Title: Thunderheader Keeps Snapping Exhaust Mounts
Post by: HotRodFXR3 on August 09, 2018, 10:31:23 AM
I have a 1999 FXR3 with a 113 S&S.  The pipe I'm running is a Thunderheader..  I have the pipe rubber mounted in the rear.  I've snapped the exhaust bolts twice.  I remember when I first got the pipe there was a mount that came off the engine right under where the cam is.  That mount broke a while ago, and I was told it didn't need to be replaced.  I'm thinking it did.  Is there a better way to mount this pipe to the engine so this doesn't keep happening?  Thanks for any and all help.
Title: Thunderheader Keeps Snapping Exhaust Mounts
Post by: HotRodFXR3 on August 09, 2018, 10:32:56 AM
I have a 1999 FXR3 with a 113 S&S.  The pipe I'm running is a Thunderheader..  I have the pipe rubber mounted in the rear.  I've snapped the exhaust bolts twice where they mount to the cylinder head.  I remember when I first got the pipe there was a mount that came off the engine right under where the cam is.  That mount broke a while ago, and I was told it didn't need to be replaced.  I'm thinking it did.  Is there a better way to mount this pipe to the engine so this doesn't keep happening?  Thanks for any and all help.
Title: Re: Thunderheader Keeps Snapping Exhaust Mounts
Post by: Rooster on August 09, 2018, 10:52:09 AM
Same happened to me from a loose p-clamp. Make sure you look over the pipe real good as mine had fine zipper cracks on the back. Had a welder weld the cracks and put it back on. Still working good even though an ugly weld is there. Nice guy only charged me $15. Bike is 96WG.
Title: Re: Thunderheader Keeps Snapping Exhaust Mounts
Post by: hd-dude on August 09, 2018, 02:08:52 PM
If I recall correctly the FXR's had a P-clamp around the header down by the cam cover. This must be installed to support the pipe. Since the pipe is mounted to the rear of the frame there is a lot of stress that occurs at the heads when the P clamp is not installed. Also be sure your front motor mount is in good shape. A worn out mount will allow excess movement of the engine in the frame.
Title: Re: Thunderheader Keeps Snapping Exhaust Mounts
Post by: Twolanerider on August 09, 2018, 04:18:04 PM
If I recall correctly the FXR's had a P-clamp around the header down by the cam cover. This must be installed to support the pipe. Since the pipe is mounted to the rear of the frame there is a lot of stress that occurs at the heads when the P clamp is not installed. Also be sure your front motor mount is in good shape. A worn out mount will allow excess movement of the engine in the frame.

Assuming his pipe still uses the stock support brackets:
Title: Re: Thunderheader Keeps Snapping Exhaust Mounts
Post by: HotRodFXR3 on August 09, 2018, 09:21:07 PM
thank you all for the replies!  I will definitely inspect the pipe when I pull it.  I'll also check the motor mounts and the rear mount.  Where can I get that mount that mounts under the cam inspection plate?  It's not a stock motor, but a S&S 113.  I do remember there being a mount there in the when I first bought the pipe, but that broke and I was told I didn't need it..I know bad advice, obviously..

Thanks again for all the help
Title: Re: Thunderheader Keeps Snapping Exhaust Mounts
Post by: Twolanerider on August 09, 2018, 09:35:10 PM
The bracket is 65670-82B.  Obsolete from Harley.  The clamp is 65302-82A.  Still shows available.

The bracket lives in the aftermarket though.  In the "ask and you shall receive" category click the link below:

https://www.ebay.com/itm/322800216444
Title: Re: Thunderheader Keeps Snapping Exhaust Mounts
Post by: Twolanerider on August 09, 2018, 09:37:23 PM
 ^^ Do an ebay search by the clamp part number while you're there.  Will likely find several if not many used or aftermarket options.  Common part on many bikes for a long time.