Yamaha TRX850 Enthusiasts Forum

I bought my TRX even though I knew this problem would bite me. When I viewed the bike in the dark I saw there was some sort of compound around the joints between the head and pipes, but I really wanted the bike as it was a 95 Japan model as they weren't exported until 96 and in white with a red frame.

Well, it's time for an mot and I noticed that the exhaust was blowing, so I thought I ought to fix it first. The first stud snapped, so I had to use a dremel on the other three nuts. On removing the Downpipes I noticed that most of the flanges had been snapped off the head which shouldn't stop me from getting a good seal, just doesn't look too good. The problem I have is with the Downpipes, the clamps are just flat steel ones which look ok but I may swap for the GPZ ones if I can, but there are mild steel tubes welded to the end of the Downpipes that the plates push against. It's these that are corroded and will stop me getting a good seal against the head. Is there anyone out there that has made these tubes or will I need to find a company that could knock them up on a lathe for me ?

Will post photos if I'm not clear enough with my problem.

Obviously aftermarket headers on it, but its the exhaust flange gasket that gives the good seal.
Buy descent gaskets or just use some roof n gutter clear silicone for an easy fix on the old one and handles the heat with no issues.

I removed the broken stud by heating up the stud until it glowed on the end and quenching with plusgas, did this about eight times, used a stud extractor and it came straight out !

Headers are the standard ones that came with the bike from new, but cannot understand why they welded mild steel tubes over the stainless pipes ? Have a workmate that has offered to make the new sleeves but I don't know anyone who can weld the mild to stainless, so I hope I can find something to bond them together as I don't think there is much stress on the joint ?

Std headers don't have a flat plate clamps.

flintstone wrote:I bought my TRX even though I knew this problem would bite me. When I viewed the bike in the dark I saw there was some sort of compound around the joints between the head and pipes, but I really wanted the bike as it was a 95 Japan model as they weren't exported until 96 and in white with a red frame.

Well, it's time for an mot and I noticed that the exhaust was blowing, so I thought I ought to fix it first. The first stud snapped, so I had to use a dremel on the other three nuts. On removing the Downpipes I noticed that most of the flanges had been snapped off the head which shouldn't stop me from getting a good seal, just doesn't look too good. The problem I have is with the Downpipes, the clamps are just flat steel ones which look ok but I may swap for the GPZ ones if I can, but there are mild steel tubes welded to the end of the Downpipes that the plates push against. It's these that are corroded and will stop me getting a good seal against the head. Is there anyone out there that has made these tubes or will I need to find a company that could knock them up on a lathe for me ?

Will post photos if I'm not clear enough with my problem.

As you seem to have a corrosion problem with your headers, most likley you are in the UK..plenty of standard exhaust header sets would be about if you ask in the Wanted section.
Also if you have flat plates for header clamps, this isn't the first time the machine has seen the problem.
So, either ask about here for a set of pipes or Google for aftermarket ..depends how deep your pockets are tho.
Sounds like someone has done a basic fix with car exhaust tube onto the origional stainless system that has not been up to the long term task.
Projection Components.com.uk make a nice two into one.

The projection components 2-1 has the added bennefit of being larger bore so better flow, plus its stainless and a good fit.

I assumed mine were different as my TRX is a 95 Japanese version as they weren't exported until 96 and the bracket bracing the downpipes and securing to the bottom of the engine is stamped 4NX-029. The bore is also 36mm which is larger than a 96 model I saw in Brighton that had the same corrosion problem with the sleeves. Wish I could upload photo's of them as the 96 version I saw in Brighton had one usual collar seen on uk models and one flat plate like mine.

Interesting your thought that the import models have a different header size,..haven't heard of this before..
Should be all the same exhaust from import UK and here in OZ
Google images on origional exhaust systems.
The origional will have a cast collar..

Mine is also a 95 early import. Frame was red when i got it. Its mostly black now.
Dave

Some of the after market Japanese exhausts stamp their header bracket 4NX under the motor. I think flat performance may be one of these??? but their is a myriad of after market exhausts on offer in Japan and a lot are just re stamped under a different brand. There are a number of systems in Japan that have copied the Over system too for an example.
Do yourself a favour, save your money and just clean up the system you have.
seal it a bit of clear roof and gutter sealant either side of your copper exhaust gasket then smear a little around the header when fitting. It will handle the heat with no issues.

cobbadiggabuddyblooo wrote:Some of the after market Japanese exhausts stamp their header bracket 4NX under the motor. I think flat performance may be one of these??? but their is a myriad of after market exhausts on offer in Japan and a lot are just re stamped under a different brand. There are a number of systems in Japan that have copied the Over system too for an example.
Do yourself a favour, save your money and just clean up the system you have.
seal it a bit of clear roof and gutter sealant either side of your copper exhaust gasket then smear a little around the header when fitting. It will handle the heat with no issues.

Roof or gutter silicone Brian ?
im used to seeing a higher level of standards from you .

windscreen silicon is my go to exhaust sealer

http://www.supercheapauto.com.au/online ... mendations

Marketing Alex... why pay big $$$ for draino when you can by caustic soda for a 1/4 of the price..

Being on the subject of cheap fixes as long as no one knows,
auto filler,.. or BOG as we call it is great gap filler in heat areas as well.
Always have a can in the cupboard.

Here is a pic of a Flat Performance street system.
headers are a couple of mm larger than std and has a 4NX stamped into the header bracket.
The Flat Performance race system is the same diameter as an Over Racing system.
Nojima do the same with a street and race system and the easiest way to tell the difference with their race system, ithas a beautifully hand bent sweeping curved header.

The std TRX headers also have a small bolt/bung in each header tube just by the balance pipe.