Front pipe leaking and vibration noise

[smitten]

Hi,

I have a 2stroke 300EC 2011. The front pipe leaking a little bit where it is attach to the engine. After a couple of ride, I can see kind of black oil leaking where it is attache to the engine. I can push on the pipe and it moving a little bit. There is a huge vibration noise too. When I moving the pipe with my hands, when the bike is on idle, the vibration disapear.

Do you guys think that if I replace the exaust o-ring and spring it will fix the problem? Or I need a new pipe?

Thanks.

smitten

 

[Neil E.]

Pipe and springs are fine (unless broken). Put in new orings. Mount the pipe, bolts only snug. Start the engine, tighten the mounting bolts up and see if the pipe still vibrates.

If it vibrates, redo the process, but push the rubber mounts around a little to put force on the rubber mounts and tighten them up. I usually need to move the mounts a bit to find the best spot to stop any vibration.

 

[Jakobi]

I usually use some high temp silicone on the spigot/O-rings as well.

Make sure the pipe is straight. If its been tweaked it'll be more inclined to vibe up.

The O-rings do wear out. My bike is doing this at the moment. Will be going onto the 3rd or 4th set of O-rings in 100hrs. Viton rubber holds up much better than normal NBR.

 

[motopsycho87]

I agree with the high temperature silicone. Make sure all the mounts are the same, and buy 0.5 or 1mm over size o rings

 

[memphis2857]

Use the green Viton o-rings that they use on KTM's


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[smitten]

Thanks a lot guys. It seem to be a common problem. You guys just save me a pipe

Cheers

 

[Phaeton]

I chased this issue for awhile. Damn skid plate was loose. Check that while your at it.

 

[Moto7man]

See post 14 on the thread below, then click on the link the post.

http://www.gasgasrider.org/forum/showthread.php?t=14173&highlight=vitron+rings&page=2

 

[Terrence R]

The exhaust flange o-rings that came with my Numaria top end gasket are def over sized. I really couldn't get the pipe on with those o-rings on the flange. I used the old ones as they were still in usable condition and a little bit of high heat sealant.

 

[Moto7man]

The exhaust flange o-rings that came with my Numaria top end gasket are def over sized. I really couldn't get the pipe on with those o-rings on the flange. I used the old ones as they were still in usable condition and a little bit of high heat sealant.

A few light taps with a rubber mallet should work.

 

[Terrence R]

A few light taps with a rubber mallet should work.

That's what I though. 2 hours later, I gave up on those o-rings. Hey: I wonder if I took the whole flange off, put the o rings on it, and throw it in the freezer for a day if it'll shrink it up enough. Maybe I could even heat up the pipe a bit with a small torch

 

[Neil E.]

If you could get a sleeve that's the same size or only slightly larger than the pipe ID, you could bevel the sleeve, grease the orings and force the parts together. Leave it for a day and the orings will change profile enough to allow the pipe to be pushed on.

 

[Terrence R]

If you could get a sleeve that's the same size or only slightly larger than the pipe ID, you could bevel the sleeve, grease the orings and force the parts together. Leave it for a day and the orings will change profile enough to allow the pipe to be pushed on.

Good point. That could be worth trying.

 

[Jakobi]

Or remove the silencer. Sometimes the added friction (and any misalignment) here can also add to issues with the header pushing on. I've noticed this on the new chasis.

 

[smitten]

Thanks again for all your info.

Cheers