Leaky aftermarket pipes

[skipevans]

Hey all,

My 87 2MA has aftermarket pipes. Don't ask me what kind. Even you guys here on the forum had never seen these guys, but I imagine the issue I'm having is something others have experienced with non-stock chambers.

It gets really messy where the pipes fit into the cylinders, lots of oil blowing out of there, enough to muck up that part of the engine, down the pipe and collect into the bottom of the lower fairing after a time.

Any suggestions on ways to make them fit better would be most appreciated.

Skip

[calgap]

Skip,

The stock pipes use a thick round ring and a flat normal gasket to seal them. These have to be in tip top condition on my bike to seal the pipes.

What sort of arrangement do you have on the manifold of yours? Can you post a picture?

Cheers,
Chris

[Yatsushiro]

I use a high temperature silicon sealant (Hondabond HT, Permatex Ultra copper etc), to effect a good seal where the pipe header fits into the manifold/flange.

Needs redoing every 2nd or 3rd race weekend.

[Northland]

Fresh set of exhaust gaskets and permatex "The right stuff" brand sealer.

The permatex is by far the best stuff period !!!  I have seen it hold pipes on sleds even when the springs broke !  You clean everything super good with lacquer thinner first and get completely dry and warm.

You can get it at most NAPA auto parts stores.  Expensive but worth it.  Not reccomended if you have to take things apart often, because it is so tough and bonds so well.  A real chore to wire wheel it off when that time comes some day.

Way, way tougher and better than any other silicone sealer, and seems fine in the exhaust heat of a 2 stroke.

[Warwick]

You should be able to seal the manifold to the barrel well enough with suitable gaskets and maybe a touch of sealant. As others have said, the slip joint used by most aftermarket pipes is more a routine maintenance thing really. Clean it well, apply the best sealant you can get when assembling. And leave it overnight to cure if possible before starting the motor up as that generally helps the quality and longevity of the seal quite a bit. It can also be worth looking at improving the sliding fit of the slip joint itself if it's unecessarily baggy so that the amount of work the sealant has to do is minimised. Oh, and make sure your springs are a good tight fit too.

On the upside, oily headers fend off the rust better than dry ones... 

[mickey]

Yup...l use double gaskets on each exhaust to seal....No leakage...

[skipevans]

I have the stock type big copper coated "crush" ring in place with the regular gaskets. That's the manifold side right? That's all okay. So I think it's just where the aftermarket pipes fit in.

The Permatex or some type of sealant sounds good. I'll give that a try. Right now it's way improved since the carbs and oil pump have been adjusted properly. Was way too rich on the new engine and very smoky. Now runs great and no flat spots or bogging down low.

[skipevans]

I got the Permatex, but I'm not sure exactly how to apply it. Once the pipe ends that fit into the cylinders are clean do you apply the sealant around the pipes, but how are down? About an inch or so, the amount that it fits into the flange?

[Martin77]

Yeah, just wipe the end of the pipe with a smear of permatex, then push into the manifold. Leave for a while to set before starting the engine (about 30mins should do it)...

[skipevans]

Sounds easy enough. As soon as the rain lets up here I'll give that a shot.

[skipevans]

Okay, today the pipes and manifolds came off (is that what those things are called?) and Permateux Ultra Copper has been applied on the gaskets, crush rings and the pipes. I'll let it  sit over night, at least. Not sure when I'll go for another ride, as I'm typically a weekend rider. But I'll post back with the results.

Thanks all for the advice!

[skipevans]

Well, not perfect but an improvement. It is still leaking on the left cylinder but definitely not as much. I suppose I can try going full down to the paper gaskets between the manifold and cylinder and re-sealing the whole package and the gaskets.

Does anyone recommend giving it another go and going further? All the way to the gaskets?

I found this gasket set on ebay UK, but if someone knows a better source for a higher quality product please let me know.

http://cgi.ebay.co.uk/YAMAHA-TDR250-TZR250-TZR-TDR-250-EXHAUST-GASKET-SET-/220637814854?pt=UK_Motorcycle_Parts&hash=item335f09e046

Skip

[Martin77]

Yes... try removing everything and starting again. sometimes you find the manifold cylinder flange gets bent (over-tightening the nuts) which makes a poor seal against the copper gaskets, so check for that.

Also some pipes have an O ring seal between the chamber and manifold which splits and falls out, these O rings are pretty notorious for not lasting long, but can be sourced from motocross suppliers if you need any.

[Northland]

Start from scratch.  Clean everything all sparkley with lacquer thinner and aerosol brake cleaner, let dry completely.

This time get permatex brand.......its actually called "THE RIGHT STUFF"  not ultra copper.

Get all new genuine YAMAHA brand exhaust gaskets.  Torque the nuts tight a small bit at a time constantly switching from nut to nut till you get them all tight.

Then clean the pipe stub and the slip in section of the aftermarket pipes with aerosol brake cleaner, let dry thouroughly.

Use "THE RIGHT STUFF" on this also. assemble and put springs on immediately.

If this dosnt work.........its HOPELESS !!!!!!!    Time to buy that 08 Ninja 250 and get rid of this hair puller money pit !!!!!     


Sidenote.........pitch the AMSOIL Interceptor and buy the right damn oil !!!!!!    Dummonde tech Z 1 .   That's at least half your problem !!