Im on my 3rd Exhaust now..

[peonpete]

As the thread title states, im on my 3rd exhaust header now on my Atm-Evo 150 GY6 scooter. I have had this scooter for about 2 years now, and the first Exhaust header literally split right below where you screw it onto the bottom of the exhaust port, it lasted maybe half a year. I bought another exhaust header, the same type - a OEM one and that to split after a year of use, it split at the same exact spot as the first pipe did, right below the exhaust port. It split in early january of this year, so i bought a THIRD header and you can see where this is going...the damn thing split after 2 months of use at the same spot again! So now i have a scooter that is largely not usable do to the same problem happening over and over again.

So do i just have bad luck or are these exhaust headers just junk? The exhaust on my 50cc is still going strong after 3 years. Anyways, I would love to buy a nice chrome or stainless steel exhaust header this time but i am not having luck finding one that would definitely fit a Atm-Evo 150. It seems that a lot of these chrome exhaust headers are not welded well per reviews, and that you have to weld it yourself to get it to install right and i dont have welding equipment.

Can anyone point me to a good exhaust header?

[Gene563]

Is the engine running lean, possibly?
How does the plug look?
I have a 150cc TaoTao, and have never had any issues with the header pipe ... the muffler clogged, probably from over-rich, but that's another story. My head pipe is slightly sooty inside and as good a shape as day one. I've had it for over a year and a half with over 3K miles.

[Irish]

The only thing that I can suggest (have done it myself , on a customers bike)is to buy a new one & before installation take it to a welding shop & have them weld it correctly. Might be slightly expensive but when compared to the cost of 3 headers it's not! Irish

P.S. Also resurface your faces or if you want to do a Rube Goldberg fix - Double up on your gaskets. I wouldn't suggest that. I always figured - "Do it right or don't do it"

[peonpete]

Originally Posted by Gene563

Is the engine running lean, possibly?
How does the plug look?
I have a 150cc TaoTao, and have never had any issues with the header pipe ... the muffler clogged, probably from over-rich, but that's another story. My head pipe is slightly sooty inside and as good a shape as day one. I've had it for over a year and a half with over 3K miles.

Thats a good question and i didnt even think of that. Originally when i bought this scooter, i kept it entirely stock and never touched the roller weights/the Cam/the Carb jets. But when that first stock muffler rusted off at the header, i bought a replacement pipe and hooked that up to a performance exhaust that i had laying around, so i havnt checked its lean/rich condition but i will say that when i went WOT and let off the gas - loud pop pop pop pops would [which sounded great i wont lie]. I assume that means it was running lean.

Here is a link to the pipe that i bought 2x now, he is still selling it.

http://www.ebay.com/itm/221541928221...%3AMEBIDX%3AIT

I do recall it being spray painted black, and it looked slightly rusty after that paint burned off. He might be selling old stock as new.

Originally Posted by Irish

The only thing that I can suggest (have done it myself , on a customers bike)is to buy a new one & before installation take it to a welding shop & have them weld it correctly. Might be slightly expensive but when compared to the cost of 3 headers it's not! Irish

P.S. Also resurface your faces or if you want to do a Rube Goldberg fix - Double up on your gaskets. I wouldn't suggest that. I always figured - "Do it right or don't do it"

Thats another alternative, im thinking of buying a welding machine off craigslist and just welding it. It feels so lame to have my header pipe break 3x over lol.

[peonpete]

Here are some pictures I took of the Muffler + The bolted on support bracket i made for it [this may need to be improved] + where it broke at under the scooter.

The muffler is this one here, i purchased this muffler literally a week or so ago. It weighs about 3 pounds on its own.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Gene563]

Pete,
When I first read this, I envisioned this split along the pipe, rather than at the seam; Reading again, I see that's what you had said.
How does this muffler and pipe fit? What I'm asking is, does it seem to line up to all the mounts or do you have to torque it into place? Maybe there is stress on it when bolted in; then vibration causes it to crack at the weak point.?.

This is the only picture I have of my muffler, but you can see where the strap attaches; it's underneath and further back, connected to posts on the swingarm.

[blueboy5000]

If you're using a muffler that attaches with straps, you have to place the strap as close to the middle as possible.

[wheelbender6]

Scrappydog and others sell these pipes where the muffler and header pipe can be replaced separately. That would save you from replacing the entire exhaust every time.
-As for the cause, I think Irish is right about checking the spark plug color and jetting to see if your exhaust gasses are just too hot.
-Exhaust header cracks are usually caused because some of the other mounting bolts that support the weight of the pipe are loose or missing. Since you have replace the exhaust, you would have noticed if that was the culprit.

[peonpete]

Sorry for the long hiatus, i got sidetracked with stuff for a while. But i I did try and weld the pipe a few days ago, and the weld took hold easily...But i was unable to get the alignment correct, so after trying several more times i gave up and ordered a new pipe and that came in today. So i have the bike back up and running and it is working fine, however i am still concerned the pipe may break again at that same point. This is the 3rd pipe now afterall and the previous 2 broke at the same point.

Originally Posted by Gene563

Pete,
When I first read this, I envisioned this split along the pipe, rather than at the seam; Reading again, I see that's what you had said.
How does this muffler and pipe fit? What I'm asking is, does it seem to line up to all the mounts or do you have to torque it into place? Maybe there is stress on it when bolted in; then vibration causes it to crack at the weak point.?.

This is the only picture I have of my muffler, but you can see where the strap attaches; it's underneath and further back, connected to posts on the swingarm.

NP on the misreading and thanks for the picture Gene its very helpful, i believe we have the same muffler to and how you have your straps is what i will try and emulate. I currently only have one strap on mine, and i think its not strong enough to take all of the pressure off the muffler pipe head, which is why its breaking at the seam there. When i first put the pipe on it does align correctly, so it must be the bracket.

I am using the top bolt hole to mount the bracket though, which is opposite of your setup. I notice you have your brackets mounted underneath, that might be why i have been having trouble with it from the beginning - simply mounting the bracket wrong and over time it caused a break at the weak point [the seam]

Ill upload a picture of my current setup, again though thanks for the pic that alone has maybe fixed the problem.

Originally Posted by blueboy5000

If you're using a muffler that attaches with straps, you have to place the strap as close to the middle as possible.

Yes i am using a muffler that needs straps, infact the muffler i have looks to be identical to what Gene563 has in the pic above your message.

[blueboy5000]

That's no good. The strap must be in the middle of the can/muffler. The stock exhaust config is not a sound set up.

[peonpete]

Originally Posted by blueboy5000

That's no good. The strap must be in the middle of the can/muffler. The stock exhaust config is not a sound set up.

Thanks, ill move it up to the middle in that case.

[peonpete]

I have moved the bracket today and drilled a new hole for it as well, the muffler is as solid as a rock now so i think the problem is fixed. Thanks for the help fellas!