D.I.Y pipe. any suggestions?

after months of looking for a pipe and having missed a couple of yz pipes off ebay (missed 1 by $1) and having budget restrictions due to saving for bike for wife, I decided to have a look inside mine. my metal fabrications skills are far better than my mechanical diagnostic skills so don't worry that i've taken the angle grinder to the pipe.

Has anyone looked inside a stock Aus pipe before?

heres some pics.



I have a couple of thoughts on this.

1 the exhaust comes to the back of the pipe then goes back through the two smaller holes, then up and out that pissy little pipe out the back. should i drill holes in the back plate to let some gas out before it goes up and around, or drill holes in the out let pipe to let gas out prior to going up and around,


2 put just a bigger outlet pipe on? you can see a collar on the outlet pipe that fits into the large hole in the exhaust, should i, get pipe same diameter as collar and fit outlet, or enlarge that hole and fit bigger outlet?

original pipe internal diameter 26 mm collar diameter 30. would 4 mm make that much difference.

your thoughts.... and don't say 'just go buy a pipe'


My buddy has a YZ pipe for sale. I am thinking around 70 bucks. PM me if interested. Otherwise, good luck---sounds like you can make a good run at it. :applause:

From your choices, I would drill holes in the back plate to let some gas out before it goes up and around.

Have you thought of taking out the backplate all together and leave the outlet pipe the same? If your metal fab skills are good, I would turn it into a straight through design.

Doesn't it just piss you off?

well it's done, about tem minutes after posting i decided to go with bigger outlet. went to friends exhaust shop, got a 3oomm peice of 38mm pipe, then got a tapered grinding bit for my drill. I drilled two extra 10 mm holes in the plate inside the pipe then fitted the new outlet and end cap back on and here it is.

here is old pipe first


here is new


looks like bought one. i'll let you know how she goes.

the outlet was 26mm and is now 38mm does this raise jetting issues?



Looks sweet, I dont think you should have any probs. :applause:

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