Seafoam??

[Bmandiego]

It coughed and choked and smoked like crazy

My dad was like that.

[PGlaves]

I did similar with a can of Seafoam. With the bike running, I hooked a tube to the vacuum port under the thottle body and let it suck in small amounts of seafoam to clean the carbon. Would work with water too and is much more controllable than pouring water in. I put a valve inline on the tubing to regulate the flow of liquid into the throttle body. It coughed and choked and smoked like crazy but hopefully cleaned things up some. It seemed to get rid of the pinging the bike was exhibiting.

Yes it works, but caution is advised. If you kill the engine while carbon is still breaking loose you may wind up with carbon bits under the exhaust valves - see post #55 meaning you get to pull the heads.

[kthflieger]

my 80 GL1100 developed a real miss which didn't go away with standard carb cleaner in the fuel tank. A shot of sea foam worked wonders! BTW - many aircraft mechanics I know soak fuel injectors in Hoppes gun cleaning solvent to clean them. I have used it as well on gunked up carb parts and it really cleans up the "stuff" left behind by bad fuel and gets rid of carbon build up.