Exhaust Sealant

10 replies to this topic
  • YZPaGuy

Posted February 24, 2013 - 05:33 PM


I am doing an overhaul on my 08. I am putting a new head pipe on in the process. It's a FMF stainless steel. I have a Lexx exhaust and mid pipe. IS there a certain type of sealant I should use where the mid pipe meets the head pipe? I was just going to use a high temp gasket maker but I'm not sure if that will work or if I should use anything at all.

Thanks for the help!

  • marv02

Posted February 24, 2013 - 06:22 PM


I always used Red High temp RTV.

  • hillclimb426

Posted February 24, 2013 - 10:44 PM


Get the copper silcone maximum temp last longer than the red in my trials and errors. I have the lex also the mount on the mid pipe is weak broke on mine three times.add a large hose clamp next to it.

  • grayracer513

Posted February 25, 2013 - 07:33 AM


There should be no need to use any sealant at all if the two pipes fit together properly.

  • YZPaGuy

Posted February 25, 2013 - 01:49 PM


Gotcha, I will check the fit tonight and then go from there. I got to get this thing finished up soon. Less then two weeks to the first race. Should be done by this weekend, I'm getting close. I will post up pics when she is all done. I can't wait for the race season to start!

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  • Nautical Miles

Posted February 26, 2013 - 01:39 AM


There should be no need to use any sealant at all if the two pipes fit together properly.

I believe this 100%, however, if ones exhaust didnt fit well and you were to use sealant would an RTV type sealant work? Or if nothing else how would one go about making them fit a little bit tighter? The only reason I ask is because my exhaust/head pipe are of the same make/model and it still seems loose. I mean if the pipes diameters were designed and made to fit and the fit ends up loosening up, aside from using a sealant, is there really a way to "crimp" (if you will) the outside pipe onto the inside? Just to prevent leaks and the small decel pop?

  • grayracer513

Posted February 26, 2013 - 07:50 AM


I wouldn't try it with titanium out of concern that it might split, but a muffler shop should be able to expand a steel header to fit more snugly into the mid pipe, and rather cheaply.

But RTV sealants will work if the gap isn't too large.

  • poppa

Posted February 26, 2013 - 04:01 PM


Use anti seize, thats what pro circuit sent in a kit i bought recently and it worked purty dam good. It mite have been their special blend but i doubt it, it was a little packet like ketchup and said "anti seize" on it.

  • grayracer513

Posted February 26, 2013 - 04:22 PM


That was, oddly enough, intended to keep them from sticking together, so they could be assembled and disassembled more easily, not as a sealant. Most aftermarket systems slip together and seal adequately without sealers, but some are a PITA to get back apart.

  • YZPaGuy

Posted February 26, 2013 - 08:57 PM


I put it all together last night, seemed to fit pretty tight. I will know when I finally ride it. Which will probably be a race in two weeks, lol. I have been busting my butt getting her all cleaned up, decorated with red and everything gone over and replaced before the race season. Been on it until 11pm the last two nights.

My latest problems;
1) The smaller engine pulg on the flywheel cover stripped out tonight. I was only removing it to put in a red plug so it would look nice. It doen't matter for short term but I'm going to have to do something with it? New flywheel cover? Try to drill it out? Remove the flywheel cover and use penetrating oil from the back side?

2) My steering stem bearings are shot again. Most likely going to just race it like that BUT, I changed them twice last year, the latest being inAugust or September. I have heard there is a mod that syas to use a KX450F seal on the top of the stem that works allot better then the Yammy one. Anyone know anything about that? Seems I'm changing my steering stem bearings way too much!

  • Family Man

Posted February 27, 2013 - 01:01 PM


I haven't had to change a steering stem bear in 5 years of heavy use. I read that pressure washers are the leading cause of seal/ bearing failure.

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