Seafoam is superb for use as a carb cleaner or gas preservative, just try to keep it off the rubber seals. The same company also makes a product called Deep Creep, which comes in an aerosol can and can be bought at any parts store. This stuff does actually foam when it is sprayed and is great for spraying into spark plug holes and down the intake and it sticks to the parts. Then just button the engine back up and let it sit overnight. If you have really dirty/sticky rings or valves this stuff will clean it right up.