After having a valve hung by grit, and doing a search on the subject.....there appears to be a problem with buildup on the valves. This inturn causes decreased compression, rough running motor, poor power and general decline. Well, my business is based around this type of problem solving. With your bikes, it is not so much the buildup of carbon, but the residue (detergent) left after the motor shuts down and the fuel evaporates, leaving the residue. This creates your so-called deposits (along with carbon). Now, you can safely and effectively remove/reduce your deposits by simply using a fuel injection cleaner mixed at a ratio of approx 40% cleaner to gas. Mix about 1qt and run your bike on it. The bike will run rough, due to incomplete combustion but, that is what you want. A mixture or solution that has a low flashpoint will burn before it can clean. A good product will be based on ammonia soap. Contrary to popular beliefs, it does not harm floats....period. My company sells equipment to Japan and China just for cleaning 2-stroke motorcycles, lawnmowers, etc and these numbers of cleanings are well into the thousands. I have used these solvents for over 20 years on my own equipment. Once you have run the solution, run clean gas afterwards, do not allow the motor to not be flushed through with clean gas, because the solidified gum, etc will reform. People say you cannot dissolve carbon, this is true. Carbon is like a cluster of grapes held together by resin which is the stem to the grapes. Resin is easily dissolved, hence releasing the carbon/grapes. Aggressive cleaning can remove too much too fast and causee a hung valve, but this is rare. So enjoy............jsut my contribution. This is not a solicitation, because my company does not sell retail.