Fuel is another thread in and of itself, but here's some information that might be useful to dispel some myths:

1. "4-Stroke" fuel is not for ALL 4-stroke engines. It is a special blend for older 4-stroke engines that required less oil. Most of today's 4-stroke engines are designed to run with regular glow fuel.
2. You can doctor your fuel mixture by adding oil. It's a simple math problem to figure out how much. Most hobby shops stock a few quarts of Sig castor oil, so if your engine can handle castor, add some to make your fuel match the manufacturer's specifications.
3. Always follow the manufacturer's recommendations for fuel. That way, if the engine fails during the warranty period, you can't give the distributor a reason to deny your warranty claim.
4. Unless the manufacturer says to use a specific "special" blend of fuel, always use regular fuel. Regular fuel is fuel that is marked with the nitro content only. It won't say "4-Stroke," "Heli," or "YS 20/20."
5. All fuels are made from the same materials: Methanol, nitromethane, and oil. The only differences between the various types of fuel are the type and percentage of oil, and the amount of nitromethane. The most important of these is the oil content. If the fuel has the right amount of the right kind(s) of oil, you're generally pretty safe.