Best way to use Sea Foam, Power Tune and similar products is to run them through the engine (mix ~ 1/3 Sea Foam, 2/3 gas, then the right amount of oil). Run the whole tank empty, let sit for an hour or so, then run engine on normal mix of gas/oil (fly it is fine). The important place to get rid of carbon is the ring lands and exhaust port area. One or two treatments should do it and no disassembly required. Sea Foam is available in NAPA stores and other auto parts places. The same product is available in an aerosol form called Deep Creep. I would spray about 1/4 can into the carb throat with engine at a fast idle, let sit for an hour then run normally. If you have much carbon, the motor may smoke for a minute or so, then clear up. I've been using this stuff for years with 2 stroke outbord motors.