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De coking an exhaust - any techniques?
StevieB - 10/7/12 at 09:09 AM

Hi all - just doing a quick scour to find any techniques to make my life easier!

I have a 2 stroke enduro bike that needs a bit of TLC following its debut at the ryedale rally last weekend (went great, but dropped out with mechanical issues before I ended up with a much more expensive problem to fix!)

I need to replace the exhaust gasket and figured I'd give the pipe a clean through while it's off. I've seen a couple of methods involving putting the pipe in a fire to burn off the carbon and knock it out and also soaking it in caustic soda. Neither of these are desirable to me in any way as I'll end up with one kind of burn or another.

I saw mention somewhere of using washing powder - has anyone tried this? Ir maybe traffic film remover left submersed overnight?

Any advice would be greatly appreciated - basically anything that's a cheap, safe method would be good. There's a chance it might need a bit of welding here and there so I just need to reduce the build up as much as possible and get a clean weld if/where needed.

Cheers

Steve


matt_gsxr - 10/7/12 at 09:25 AM

I guess liquid oxygen isn't appropriate in this case then!


balidey - 10/7/12 at 09:47 AM

The only 2 ways I ever did it were...

1: Heat up with gas torch then smack it with a hammer. Not nice, not pretty but it worked.

2: Buy new exhaust.


Wheels244 - 10/7/12 at 10:21 AM

I had this with my Fantic many moons ago.
I heated it up using oxy/acetylene gear with a wide heating nozzle.
Smoked like hell whilst burning the oil off, but worked - just shook the carbon out afterwards.
Resprayed the exhaust with heat resistant paint - sorted.
It ran MUCH better afterwards.


MikeCapon - 10/7/12 at 10:47 AM

quote:
Originally posted by Wheels244
I had this with my Fantic many moons ago.
I heated it up using oxy/acetylene gear with a wide heating nozzle.
Smoked like hell whilst burning the oil off, but worked - just shook the carbon out afterwards.
Resprayed the exhaust with heat resistant paint - sorted.
It ran MUCH better afterwards.



I road raced 2 strokes for years. This is the only way to go. All the other methods were, in my experience, useless.


steve m - 10/7/12 at 11:06 AM

Didnt we all take the exhaust off, and bang a potato in the inlet pipe to seal it and then fill the exhaust up with a caustic soda mix,
leave it over night to dissolve the coke/carbon, and empty the gueee mess into the drain the following day ?

seemed to work for me back in the 70's also with a flexible drill attachment with a small wire brush wizzed it up and down the exhaust
start up, and rev, and watch millions of bits of crud go over next doors garden


Well, thats what i did!


steve m - 10/7/12 at 11:11 AM

http://uk.video.search.yahoo.com/video/play?fr=yfp-t-702&fr2=piv-web&c=17&p=removing+exhaust+carbon&vid=7f886fc33cd1323010be880f40fa23 33&dt=1274832000&l=0&turl=http%3A%2F%2Fts3.mm.bing.net%2Fvideos%2Fthumbnail.aspx%3Fq%3D4592467438731314%26id%3D64e9b792babedde3474e6866f89 f300c%26bid%3DM0uyW3VG3eDUdQ%26bn%3DLargeThumb%26url%3Dhttp%253a%252f%252fwww.youtube.com%252fwatch%253fv%253dgl3s73CM9zQ&rurl=http%3A%2F%2Fwww.yo utube.com%2Fwatch%3Fv%3Dgl3s73CM9zQ&tit=Cleaning+a+motorcycle+exhaust&sigr=11aemht8o&newfp=1


owelly - 10/7/12 at 01:58 PM

Drop it off here and I'll pop it on the BBQ. I used to slosh a bit of paraffin around inside the chimney and then set fire to it. Then drop it in a water-butt. All the sooty crap would float to the top.


quinnj3 - 10/7/12 at 02:30 PM

I de-coked my inlet manifold from my diesel car at the weekend there. The only thing that would do any good at all was Mr Muscle oven cleaner


StevieB - 10/7/12 at 02:30 PM

I thought about the fire/bbg route or even using a heat gun aimed straight up the chimbley and left to do its thing but fear the neighbours will not be happy bunnies.

I was hoping there'd be something non-noxious that I could use and pour down the drain or on the garden without fear of poisoning the cat/children/fish etc.