How To Clean A Two Stroke Exhaust

Anyone have any experience decarbing a two stroke exhaust system? I've narrowed down my smoking problems to carbon build up in my exhausts. They are the only part of the project that wasn't throughly cleaned because I keep telling myself that I'll find some expansion chambers.

I've looked into it a bit and most people just say to dump a cleaner in the fuel tank and cylinders, as much carbon as two strokes build up, I'm not so confident that's going to do it.

It's a Suzuki T250

crazypj

Split personality, I fake being smart

I 'have some experience' with these :
There is an inner perforated 'silencer' and packing of some sort forming 3 layers on entire 'silencer ' section.
It's about 1/4" thick and when soaked with oil make silencer really heavy.
Using Oxy/acetelene it's possible to heat one end to red, turn off DA and feed neat oxy into pipe.
You can watch the inner section burning out by watching the red hot 'ring' that forms.
It turns pipe into an expansion chamber as NOTHING is left inside.
It may also get you arrested as the smoke is incredibly thick and it takes a while to completely burn out.
Fire brigade will be called by someone ;D
The oven cleaner is probably safest way to go or find radiator shop willing to do it (most places wont be aware it will contaminate their dunk tank beyond recovery and remove any chrome on pipes/silencer)

Kong

Been Around the Block

I've never done it on a motorcycle, but I've done it dozens of times with 2-stroke boat engines. I always used either Sea Foam or a decarb spray that Yamaha makes. You start the engine and let it warm up, then set it at a high idle. You start spraying the stuff in each carb, one after the other and you spray until the engine starts to miss. Finally, as the can nears empty, you spray it all in and if it kills the engine that's OK, if not just as it sprays out shut the engine down. Let it sit for between 30 minutes and an hour and then start it back up - and don't let anyone stand behind the exhaust when you do.

Well, I decided to spray them with oven cleaner and let them sit overnight. Used two full cans of foaming oven cleaner in each (one from each side) than pressure washed.

I'd say it definitely did the trick. Loads of carbon came out for about 5 minutes on each pipe. By the time I was done the water was clean and banging on the pipes didn't cause any carbon to break off. Remounted the exhausts and within 5 minutes was smoke freeeeeeee

"Burnin' oil and smellin' royal!"